1. J. Homola, S. S. Yee, and G. Gauglitz, Surface plasmon resonance sensors: Review, Sens. Actuators B Chem. 54(1-2), 3-15 (1999). [CrossRef] 2. R. C. Jorgenson and S. S. Yee, A fiber optic chemical sensor based on surface plasmon resonance, Sens. Actuators B Chem. 12(3), 213-220 (1993). [CrossRef] 3. J. Homola, Surface Plasmon Resonance Based Sensors (Springer, Berlin, 2006).. 4. J. Čtyroký, J. Homola, and M. Skalský, Tuning of spectral operation range of a waveguide surface plasmon resonance sensor, Electron. Lett. 33(14), 1246-1248 (1997). [CrossRef] 5. R. Slavík, J. Homola, J. Čtyroký, and E. Brynda, Novel spectral fiber optic sensor based on surface plasmon resonance, Sens. Actuators B Chem. 74(1-3), 106-111 (2001). [CrossRef] 6. P. Schuck, Use of surface plasmon resonance to probe the equilibrium and dynamic aspects of interactions between biological macromolecules, Annu. Rev. Biophys. Biomol. Struct. 26(1), 541-566 (1997). [CrossRef] [PubMed] 7. M. Malmqvist, Surface ...

We report a simple label-free localized surface plasmon resonance sensor that uses the multiple resonances of a U-shaped gold nanostructure to differentiat

In this study, a rationally-designed 2,4,6-trinitrotoluene (TNT) binding peptide derived from an amino acid sequence of the complementarity-determining region (CDR) of an anti-TNT monoclonal antibody was used for TNT detection based on a maleimide-functionalized surface plasmon resonance (SPR) sensor. By antigen-docking simulation and screening, the TNT binding candidate peptides were obtained as TNTHCDR1 derived from the heavy chain of CDR1, TNTHCDR2 derived from CDR2, and TNTHCDR3 from CDR3 of an anti-TNT antibody. The binding events between candidate peptides and TNT were evaluated using the SPR sensor by direct determination based on the 3-aminopropyltriethoxysilane (APTES) surface. The TNT binding peptide was directly immobilized on the maleimide-functionalized sensor chip surface from N-γ-maleimidobutyryl-oxysuccinimide ester (GMBS). The results demonstrated that peptide TNTHCDR3 was identified and selected as a TNT binding peptide among the other two candidate peptides. Five kinds of TNT

We have rationally designed two-dimensional Au and Ag hole arrays for high performing surface plasmon resonance (SPR) sensing. The figure-of-merit (FOM), which is defined as sensitivity/linewidth, is found to be highly geometry-dependent. For sensitivity, we find it is equal to the period of array when exciting low order surface plasmon modes at low incident angle. Therefore, increasing period improves sensitivity. On the other hand, narrow linewidth can be obtained from small hole size so that the radiative decay loss is minimized. By using a pair of orthogonally oriented polarizer and analyzer, the signal-to-noise ratio (SNR) can be greatly enhanced due to the elimination of the nonresonant reflection background. As a proof of our strategy, we have obtained FOM larger than 100/RIU and SNR higher than 110 from Au arrays. Our results show the importance of understanding the basic properties of surface plasmon polaritons in order to systematically optimize the performance of the plasmonic system ...

BioAssay record AID 642885 submitted by ChEMBL: Binding affinity to chicken riboflavin binding protein by surface plasmon resonance assay.

The surface plasmon resonance (SPR) phenomenon is utilized in a number of new real time biosensors. In this study, we have used this technique to study interactions between the central complement component C3b and its multiple ligands by using the Biacore equipment. The SPR technique is particularly suitable for analysis of the alternative complement pathway (AP) because the inherent nature of the latter is to amplify deposition of C3b on various surfaces. C3b was coupled onto the sensor surface and the coupling efficiency was compared under various conditions on both polystyrene and carboxymethylated dextran surfaces. After enzymatic C3b coupling or standard amine C3b coupling, we analyzed and compared the binding of four C3b ligands to the surface: factor B, factor H, C5 and the soluble complement receptor 1 (sCR1, CD35). Binding of each ligand to C3b was detected when C3b had been coupled either enzymatically or using the amine coupling, but the half-lives of the interactions were found to ...

0035] Generally stated, the non-limitative illustrative embodiment described hereinafter relates to a high sensitivity plasmonic structure for use in a surface plasmon resonance (SPR) sensor, and a method of fabrication thereof. The plasmonic structure comprises an array of microholes defining triangles of 700 nm, 950 nm and 1.8 μm edge lengths, which transition to propagating SPR with microhole arrays of decreasing size. Such microhole arrays exhibit a short range SPR mode (as measured in the Kretschmann configuration SPR). Triangle arrays of different sizes and aspect ratio generally exhibit two absorption bands and a transmission maximum in the SPR spectrum. The maximum in transmission at approximately λ=600 nm exhibits the best analytical characteristics for triangle arrays. This maximum shifts significantly with increasing refractive index (RI) for the triangles of 950 nm and 1.8 μm edge lengths, with a sensitivity of 1993 and 1038 nm/RI respectively. This high sensitivity is comparable ...

1996 (English)In: 3: rd Meeting and Seminar on : Ceramics,Cells and Tissues, (Ed. Ravaglioli,A. and Krajewski,A.). Gruppo editoriale faenza editrice s.p.a., 1996, 171-178 p.Conference paper, Published paper (Other scientific) ...

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TY - JOUR. T1 - Enhancement of surface plasmon resonance sensing for DNA hybridization using colloidal Au attached probe DNA. AU - Yamaguchi, Akira. AU - Juodkazis, Saulius. AU - Matsuo, Shigeki. AU - Misawa, Hiroaki. PY - 2002/2/5. Y1 - 2002/2/5. N2 - In this study, we demonstrate that the Au particle modified probe DNA monolayer can enhance the surface plasmon resonance (SPR) signal for measuring hybridization of unlabeled DNA molecules. The Au particles adsorbed on single stranded (ss)- and double stranded (ds)-DNA monolayers have different optical interaction with surface of Au thin film, and this difference induces the enhancement of the SPR signal.. AB - In this study, we demonstrate that the Au particle modified probe DNA monolayer can enhance the surface plasmon resonance (SPR) signal for measuring hybridization of unlabeled DNA molecules. The Au particles adsorbed on single stranded (ss)- and double stranded (ds)-DNA monolayers have different optical interaction with surface of Au thin ...

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TY - JOUR. T1 - Differential roles of ionic, aliphatic, and aromatic residues in membrane - Protein interactions. T2 - A surface plasmon resonance study on phospholipases A2. AU - Stahelin, R. V.. AU - Cho, W.. PY - 2001/4/17. Y1 - 2001/4/17. N2 - The roles of cationic, aliphatic, and aromatic residues in the membrane association and dissociation of five phospholipases A2 (PLA2), including Asp-49 PLA2 from the venom of Agkistodon piscivorus piscivorus, acidic PLA2 from the venom of Naja naja atra, human group IIa and V PLA2s, and the C2 domain of cytosolic PLA2, were determined by surface plasmon resonance analysis. Cationic interfacial binding residues of A. p. piscivorus PLA2 (Lys-10) and human group IIa PLA2 (Arg-7, Lys-10, and Lys-16), which mediate electrostatic interactions with anionic membranes, primarily accelerate the membrane association. In contrast, an aliphatic side chain of the C2 domain of cytosolic PLA2 (Val-97), which penetrates into the hydrophobic core of the membrane and ...

Autor: Kobayashi, K. et al.; Genre: Zeitschriftenartikel; Im Druck veröffentlicht: 2002-08; Titel: Monolayer formation of cytochrome b(562) on gold surfaces and its reconstitution reaction, studied by surface plasmon resonance spectroscopy

TY - JOUR. T1 - Sequential analysis of multiple analytes using a surface plasmon resonance (SPR) biosensor. AU - Chung, J. W.. AU - Bernhardt, R.. AU - Pyun, J. C.. PY - 2006/4/20. Y1 - 2006/4/20. N2 - A sequential analysis method for the analysis of two analytes was developed using a surface plasmon resonance (SPR) biosensor. A sample with both analytes was introduced into the single sensing region and then each analyte was analyzed sequentially. Two detection models were devised for the samples with the following composition: (1) one target analyte resulting in a sensor response without any label and the other analyte with only additional label, (2) both target analytes requiring additional labels for detection. A standard curve for each model was prepared and applied for sequential analysis of anti-bovine serum albumin (anti-BSA) antibodies and horseradish peroxidase (HRP). The errors of the sequential analysis of Models 1 and 2 were found to be less than 6%, and this method was therefore ...

Protein sequence and surface plasmon resonance analysis of the anti-IGFBP7 sdAb 4.43. (A) Protein sequence of anti-IGFBP7 sdAb 4.43; CDR1, CDR2 and CDR3 are und

en] Surface plasmon resonance (SPR)-based biosensors are very powerful tools for the study of biomolecular interactions, chemical detection and immunoassays. This paper reviews the performance of various SPR structures and detection schemes focusing on propagating surface plasmons generated in planar structures. Some aspects of their surface functionalization, the key element which imparts biofunctionality to these structures and hence transforming them into biosensors, will also be discussed accordingly. The ultimate performance of SPR-based biosensors will thus be determined by both their inherent optical performance and suitable surface functionalization. (C) 2011 Elsevier Ltd. All rights reserved ...

Using synthetic Tn (GalNAc-O-Ser/Thr) glycopeptide models and a biosensor based on surface plasmon resonance spectroscopy we have determined that isolectin B4 from Vicia villosa (VVLB4) binds to one Tn determinant whereas the anti-Tn monoclonal antibodies 83D4 and MLS128 require at least two Tn residues for recognition. When an unglycosylated amino acid is introduced between the Tn residues, both antibodies do not bind. MLS128 affinity was higher on a glycopeptide with three consecutive Tn residues. These results indicate that Tn residues organized in clusters are essential for the binding of these antibodies and indicate a different Tn recognition pattern for VVLB4.

Dr. Zeczycki from East Carolina University, uses OpenSPRs surface plasmon resonance technology to get the key binding data needed for their recent publication on protein-lipid interaction.

TY - JOUR. T1 - Surface plasmon resonance phase imaging measurements of patterned monolayers and DNA adsorption onto microarrays. AU - Halpern, Aaron R.. AU - Chen, Yulin. AU - Corn, Robert M.. AU - Kim, Donghyun. PY - 2011/4/1. Y1 - 2011/4/1. N2 - The optical technique of surface plasmon resonance phase imaging (SPR-PI) is implemented in a linear microarray format for real-time measurements of surface bioaffinity adsorption processes. SPR-PI measures the phase shift of p-polarized light incident at the SPR angle reflected from a gold thin film in an ATR Kretschmann geometry by creating an interference fringe image on the interface with a polarizer-quartz wedge depolarizer combination. The position of the fringe pattern in this image changes upon the adsorption of biomolecules to the gold thin film. By using a linear array of 500 μm biosensor element lines that are perpendicular to the interference fringe image, multiple bioaffinity adsorption measurements can be performed in real time. Two ...

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Bioelectron. 19, 1497-1504. Oh, B. , Chun, B. , Bae, Y. , Lee, W. , and Choi, J. W. (2005). The fabrication of protein chip based on surface plasmon resonance for detection of pathogens. Biosens. Bioelectron. 20, 1847-1850. , and Matsunaga, T. (1999). Electrochemical detection of allergen in small-volume whole blood using an array microelectrode: A simple method for detection of allergic reaction. Biotechnol. Bioeng. 65, 480-484. Okrend, A. J. , Rose, B. , and Lattuda, C. P. (1992). Isolation of Escherichia coli O157:H7 using O157 specific antibody coated beads. Lee, W. , and Choi, J. W. (2005). The fabrication of protein chip based on surface plasmon resonance for detection of pathogens. Biosens. Bioelectron. 20, 1847-1850. , and Matsunaga, T. (1999). Electrochemical detection of allergen in small-volume whole blood using an array microelectrode: A simple method for detection of allergic reaction. Biotechnol. Bioeng. 65, 480-484. Okrend, A. J. , Rose, B. , and Lattuda, C. P. (1992). Isolation ...

An integrated optical waveguide type surface plasmon resonance (SPR) sensor having an optical waveguide with a corresponding SPR sensing area, photodetectors, and wavelength tunable laser or any kind of external tunable laser source/coupler formed on a substrate. In an embodiment, the laser is a wavelength tunable laser and optionally, the integrated device may include a power source on the substrate for providing a electric power to the wavelength tunable laser and the photodetectors, or a circuit for signal processing, or a microfluidic structure for routing a target sample to the SPR sensor area. The microfluidic structure optionally includes a mixer or a reaction chamber for mixing and allowing a physical or chemical reaction to occur, respectively. In an embodiment, plural planar integrated optical waveguide type SPR sensors may be fabricated on a substrate to form an array of SPR sensors.

Surface Plasmon Resonance (SPR) is created by surface plasmons, coherent electron oscillations existing between any two materials where the real part of the dielectric function changes sign across the interface. SPR technology is based on the electromagnetic field component of incident light penetrating into a surface and it can be used to detect molecular adsorption on surfaces.. Plasmon excitation typically exists in two configurations: the Kretschmann-Raether configuration, where a thin metal film is sandwiched between a dielectric and air, and the incident wave is from the dielectric side; and the Otto configuration, where an air gap exists between the dielectric and the metal. Using COMSOL Multiphysics, the effect of the SPR on the electromagnetic field can be defined, which has allowed for the measurement of surface contaminants and nano-scale photonic devices.. ...

0082] SPRi detection of biomolecular-binding interactions was performed using the SPRi Lab+ apparatus equipped with an 800 nm LED source, CCD camera and a flow cell (GenOptics, France), placed in Memmert Peltier-cooled incubator (Rose Scientific, Canada) for temperature control (for detailed system specifications, see L. Malic, B. Cui, M. Tabrizian, T. Veres, Nanoimprinted plastic substrates for enhanced surface plasmon resonance imaging detection, Opt. Express, 17, 20386-92 (2009)). The entire biochip surface was imaged during the angular scan, while for each experiment three ˜500 μm diameter spots were selected for the monitoring of the binding interactions with both the probe and the control. For each spot, the reflected intensity was displayed as a function of angle in the plasmon curve diagram. The slope of the plasmon curves was automatically computed to facilitate the selection of the working angle for kinetic analysis, which corresponded to the point of the plasmon curve at which the ...

The simultaneous detection of multiple analytes is an important consideration for the advancement of biosensor technology. Currently, few sensor systems possess the capability to accurately and precisely detect multiple antigens. This work presents a simple approach for the functionalization of sensor surfaces suitable for multichannel detection. This approach utilizes self-assembled monolayer (SAM) chemistry to create a nonfouling, functional sensor platform based on biotinylated single-stranded DNA immobilized via a streptavidin bridge to a mixed SAM of biotinylated alkanethiol and oligo(ethylene glycol). Nonspecific binding is minimized with the nonfouling background of the sensor surface. A usable protein chip is generated by applying protein-DNA conjugates which are directed to specific sites on the sensor chip surface by utilizing the specificity of DNA hybridization. The described platform is demonstrated in a custom-built surface plasmon resonance biosensor. The detection capabilities of ...

Shifting of the surface plasmon resonance wavelength induced by the variation of the thickness of insulating spacer between single layer graphene and Au nanoparticles is studied. The system demonstrates a blue-shift of 29 nm as the thickness of the spacer layer increases from 0 to 15 nm. This is due to the electromagnetic coupling between the localized surface plasmons excited in the nanoparticles and the graphene film. The strength of the coupling decays exponentially with a decay length of d/R = 0.36, where d is the spacer layer thickness and R is the diameter of the Au nanoparticles. The result agrees qualitatively well with the plasmon ruler equation. Interestingly, a further increment of the spacer layer thickness induces a red-shift of 17 nm in the resonance wavelength and the shift saturates when the thickness of the spacer layer increases above 20 nm. © 2012 Optical Society of America ...

TY - JOUR. T1 - Fluorescence correlation spectroscopy in surface plasmon coupled emission microscope. AU - Borejdo, J.. AU - Calander, N.. AU - Gryczynski, Z.. AU - Gryczynski, I.. PY - 2006. Y1 - 2006. N2 - Study of dynamics of single molecules by Fluorescence Correlation Spectroscopy (PCS) requires that the rate of photon detection per molecule be high, that the background be low, and that there be a large change in fluorescent signal associated with change in a position of a molecule. PCS applied to microscopic Surface Plasmon Coupled Emission (SPCE) suggests a powerful method to meet those requirements. In this method, the observational volume is made shallow by placing a sample on a thin metal film and illuminating it with the laser beam at Surface Plasmon Resonance (SPR) angle through high numerical aperture objective. The illuminating light excites surface plasmons in the metal film that produce an evanescent wave on the aqueous side of the interface. The thickness of the detection volume ...

The development of a novel electrochemically stable host-guest supramolecular complex at a host surface is described. It was constructed by combining a self-assembled monolayer (SAM) of mono-(6-deoxy-6-mercapto)-beta-cyclodextrin (beta CDSH), iron (III) tetra-(N-methyl-4-pyridyl)-porphyrin (FeTMPyP) as the guest-link-molecule and beta-cyclodextrin-functionalized gold nanoparticles (beta CDAuNP). The building process of the layer-by-layer assembly was monitored by surface plasmon resonance spectroscopy (SPR). The binding processes between the host-functionalized gold surface and the linker molecule (FeTMPyP) were verified to be monovalent, and for host-functionalized gold nanoparticles with FeTMPyP, the interaction was determined to be bivalent. Finally, the electrochemical properties of the electroactive supramolecular multivalent film were determined. (C) 2009 Elsevier B.V. All rights reserved ...

In this study, we performed finite element method (FEM) simulations to optimize the configuration of gold nanorods (GNR) enhanced surface plasmon resonance (SPR) sensor and discovered its application for multiplex antigens detection. Our work analyzed the near-field coupling between the sensing film and GNR. By systematically study the effect of gold film thickness, GNR-to-film distance and GNR dimensions on SPR, it was found that for GNR width smaller than 40nm, length change in GNR brought about significant SPR wavelength shift on the sensor, while the sensor is insensitive for GNR-to-film distance. As an application, we adopted GNRs of width 20 nm and aspect ratios from 2 to 4 and demonstrated the concept of conjugating gold film and GNRs with anti-Immunoglobulin G (anti-IgG) antibodies for multiplex detection of various IgG proteins with more than 100nm separation on their SPR wavelengths ...

Nanoparticles have offered many diverse capabilities in bioanalysis and biotechnological applications, due to the intrinsic properties of nanoparticle that is distinguished from bulk materials. The integration of nanoparticle, which exhibit unique electronic, photonic, and catalytic properties with biomaterial, which display unique recognition, catalytic, and inhibition property yields novel hybrid nanobiomaterial with synergic properties and functions. In this study, gold (Au) nanoparticle-antibody conjugate was applied for the signal enhancement of surface plasmon resonance (SPR). When small molecule is a target for immobilization or detection, the changes in the angle-dependent attenuated total reflectance (ATR) are often small so the use of SPR method is limited for generic application. The specific interaction between target molecules and Au nanoparticleantibody conjugate induce the change of the surface properties such as mass and roughness, which can be represented as the change of plasmon

Pope ME, Soste MV, Eyford BA, Anderson NL, Pearson TW. Anti-peptide antibody screening: selection of high affinity monoclonal reagents by a refined surface plasmon resonance technique. J Immunol Methods. 2009 Feb 28;341(1-2):86-96. Epub 2008 Nov 28. PMID: ...

Pope ME, Soste MV, Eyford BA, Anderson NL, Pearson TW. Anti-peptide antibody screening: selection of high affinity monoclonal reagents by a refined surface plasmon resonance technique. J Immunol Methods. 2009 Feb 28;341(1-2):86-96. Epub 2008 Nov 28. PMID: ...

Surface Plasmon Resonance (SPR) is a powerful label free optical biosensing technology that relies on the measurement of the refractive index or change of mass in close vicinity of the sensor surface. Therefore, there is an experimental limitation in the molecular weight of the molecule that can be detected and consequently small molecules are intrinsically more difficult to detect using SPR. One approach to overcoming this limitation is to first adsorb smaller molecules onto the sensor surface, and to follow this by using their higher molecular weight antibodies counterparts which ensure the specificity (and are easier to detect via SPR due to their higher weight). Although this has been demonstrated with some success, it is not applicable in every case and some biomolecules such as enzyme are still difficult to detect due to their specific reactivity (enzymatic reaction). In this paper, we present a powerful new method that utilises specifically engineered spacers attached on one end to the ...

B-lymphocyte antigen CD22 is a member of the recently described sialoadhesin family of immunoglobulin-like cell-surface glycoproteins that bind glycoconjugates terminating in sialic acid. One prominent ligand for CD22 is the highly glycosylated leukocyte surface protein CD45. Using surface plasmon resonance spectroscopy, we characterized the interaction of recombinant mouse CD22 with native CD45 purified from rat thymus (CD45-thy). By in situ desialylation and resialylation of immobilized CD45-thy, we show that mouse CD22 binds to the sialoglycoconjugate NeuGc alpha 2-6Gal beta 1-4GlcNAc carried on CD45-thy N-glycans. Previous studies have shown that the sialic acid-binding site lies within the two membrane-distal domains of CD22 (domains 1 and 2), which are V-set and C2-set immunoglobulin superfamily domains, respectively. To further localize the binding site, we have made 42 single amino acid substitutions throughout both domains. All 12 mutations that abrogated binding to CD45-thy without disrupting

The human organism employs G protein coupled receptors (GPCRs), cell surface receptors in the plasma membrane, to transmit extracellular signals such as hormones, neurotransmitters, gustatory and olfactory signals into the interior of the cell. Specific binding of these extracellular ligands induces a conformational change in GPCRs, which allows the interaction with heterotrimeric G proteins and the catalysis of GDP/GTP nucleotide exchange in the G protein. The G protein then transmits the signal by protein-protein interaction to intracellular effector proteins. The publications summarized here on the rhodopsin/transducin system of photoreceptor cells, a model system for GPCRs/G proteins, cover three topics: 1. Methodology developments for biophysical monitoring of the interaction between rhodopsin and transducin by light scattering and evanescent field techniques, in particular surface plasmon resonance spectroscopy. 2. Formation of the active conformation of rhodopsin. The temporal sequence of ...

Original Research and Commentary on p28 CDG Therapeutics Lead Agent and Analogs. Binding of Amphipathic Cell Penetrating Peptide p28 to Wild Type and Mutated p53 as studied by Raman, Atomic Force and Surface Plasmon Resonance spectroscopies.. Signorelli S, Santini S, Yamada T, Bizzarri AR, Beattie CW, Cannistraro S.. Biochim Biophys Acta. 2017 Apr;1861(4):910-921.. Phase 1 trial of p28 (NSC745104), a non-HDM2-mediated peptide inhibitor of p53 ubiquitination in pediatric patients with recurrent or progressive central nervous system tumors: A Pediatric Brain Tumor Consortium Study.. Lulla RR, Goldman S, Yamada T, Beattie CW, Bressler L, Pacini M, Pollack IF, Fisher PG, Packer RJ, Dunkel IJ, Dhall G, Wu S, Onar A, Boyett JM, Fouladi M.. Neuro Oncol., 2016 Sep;18(9):1319-25. p28-mediated Activation of p53 in G2/M Phase of the Cell Cycle Enhances the Efficacy of DNA Damaging and Antimitotic Chemotherapy.. Yamada T, Das Gupta TK, Beattie CW.. Cancer Res. 2016 Feb 26; 76(8): 2354-2365. Chirality ...

A surface plasmon resonance (SPR) apparatus was used to investigate blood plasma coagulation in real-time as a function of thromboplastin and heparin concentrations. The physical reason for the SPR signal observed is discussed and 3 different models are proposed. The response curves were analyzed by multivariable curve fitting followed by feature extraction. Interesting parameters of the sigmoid curves were lag time, slope and maximum response. When thromboplastin concentrations were increased, the lag-time decreased and the slope of the curve increased. A prolonged clotting time was followed mostly by increased maximum response, with exception for samples with no or very little thromboplastin added. High heparin concentrations changed the clotting kinetics. As seen from the lag-time vs. slope relation. Atomic force microscopy pictures of sensor surfaces dried after completed clotting, revealed differences in fibrin network structures as a function of thromboplastin concentration, and fiber ...

Abstract. Continuously monitoring cell cultures is essential for both controlling critical parameters and improving understanding of key processes. An ideal technique in this context is surface plasmon resonance (SPR) spectroscopy, which essentially exploits changes in the angle of incident light that occur when molecules bind to a surface. It provides the ability to monitor real-time changes in small concentrations of various molecules, with no need for additional labels or sample preparation. Here we present an SPR-based immunoassay for monitoring concentrations of human serum albumin (HSA), and compare its sensitivity when used in conjunction with a Biacore platform and the cheaper, smaller liSPR system. In conjunction with either system, the immunoassay can detect HSA (a hepatocyte viability marker) at concentrations typically present in three-dimensional hepatocyte cultures mimicking the liver used to evaluate effects of drug candidates before exposure to humans or animals. Furthermore, in ...

The CD8 coreceptor of cytotoxic T lymphocytes binds to a conserved region of major histocompatibility complex class I molecules during recognition of peptide-major histocompatibility complex (MHC) class I antigens on the surface of target cells. This event is central to the activation of cytotoxic T lymphocyte (CTL) effector functions. The contribution of the MHC complex class I light chain, beta(2)-microglobulin, to CD8alphaalpha binding is relatively small and is mediated mainly through the lysine residue at position 58. Despite this, using molecular modeling, we predict that its mutation should have a dramatic effect on CD8alphaalpha binding. The predictions are confirmed using surface plasmon resonance binding studies and human CTL activation assays. Surprisingly, the charge-reversing mutation, Lys(58) --| Glu, enhances beta(2)m-MHC class I heavy chain interactions. This mutation also significantly reduces CD8alphaalpha binding and is a potent antagonist of CTL activation. These results suggest a

Objective To identify the epitopes recognized by autoantibodies targeting platelet-derived growth factor receptor α (PDGFRα) in systemic sclerosis (SSc) and develop novel assays for detection of serum anti-PDGFRα autoantibodies. Methods Epstein-Barr virus-immortalized B cells from 1 patient with SSc (designated PAM) were screened for expression of IgG binding to PDGFRα and induction of reactive oxygen species in fibroblasts. The variable regions of anti-PDGFRα IgG were cloned into an IgG expression vector to generate distinct recombinant human monoclonal autoantibodies (mAb), which were characterized by binding and functional assays. The epitopes of anti-PDGFRα recombinant human mAb were defined by molecular docking, surface plasmon resonance binding assays, screening of a conformational peptide library spanning the PDGFRα extracellular domains, and expression analyses of alanine-scanned PDGFRα mutants. Direct or competitive enzyme-linked immunosorbent assays were established to detect ...

Calcium-calmodulin (CaM) binding to the epidermal growth factor receptor (EGFR) has been shown to both inhibit and stimulate receptor activity. CaM binds to the intracellular juxtamembrane (JM) domain (Met645-Phe688) of EGFR. Protein kinase C (PKC) mediated phosphorylation of Thr654 occurs within this domain. CaM binding to the JM domain inhibits PKC phosphorylation and conversely PKC mediated phosphorylation of Thr654 or Glu substitution of Thr654 inhibits CaM binding. A second threonine residue (Thr669) within the JM domain is phosphorylated by the mitogen-activated protein kinase (MAPK). Previous results have shown that CaM interferes with EGFR-induced MAPK activation. If and how phosphorylation of Thr669 affects CaM-EGFR interaction is however not known.In the present study we have used surface plasmon resonance (BIAcore) to study the influence of Thr669 phosphorylation on real time interactions between the intracellular juxtamembrane (JM) domain of EGFR and CaM. The EGFR-JM was expressed as ...

Gelatinase B (MMP-9) and galectin-3 are widely known to participate in tumor cell invasion and metastasis. Glycans derived from MMP-9 expressed in MCF-7 breast cancer and THP-1 myeloid leukemia cells were compared with those from MMP-9 expressed in natural neutrophils. The many O-linked glycans of neutrophil gelatinase B presented a cluster of mainly galactosylated core II structures, 46% of which were ligands for galectin-3; 11% contained two to three N-acetyllactosamine repeating units that are high-affinity ligands for the lectin. The glycan epitopes thus provide MMP-9 with both high-affinity and (presumably) high-avidity interactions with galectin-3. In contrast, the O-glycans released from MMP-9 expressed in MCF-7 and THP-1 cells were predominantly sialylated core I structures. Only 10% of MCF-7 and THP-1 gelatinase B O-glycans were ligands for galectin-3 and contained only a maximum single N-acetyllactosamine repeat. Consistent with the glycan analysis, surface plasmon resonance binding ...

Protein-Flavonoid Interaction Studies by a Taylor Dispersion Surface Plasmon Resonance SPR Technique: A Novel Method to Assess Biomolecular Interactions. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.

Several proteins, like transcription factors, bind to certain DNA sequences, thereby regulating biochemical pathways that determine the fate of the corresponding cell. Due to these key positions, it is indispensable to analyze protein-DNA interactions and to identify their mode of action. Surface plasmon resonance is a label-free method that facilitates the elucidation of real-time kinetics of biomolecular interactions. In this article, we focus on this biosensor-based method and provide a detailed guide how SPR can be utilized to study binding of proteins to oligonucleotides. After a description of the physical phenomenon and the instrumental realization including fiber-optic-based SPR and SPR imaging, we will continue with a survey of immobilization methods. Subsequently, we will focus on the optimization of the experiment, expose pitfalls, and introduce how data should be analyzed and published. Finally, we summarize several interesting publications of the last decades dealing with ...

Although it has been revealed that astrocytes, generally known as star-shaped glial cells, play critical roles in the functions of central nervous system, there have been few efforts to directly modul... Tags: intracellular calcium, near infrared, localized surface plasmon resonance, astrocytes, gold nanorods.

Evaluation of cytochrome c affinity to anionic phospholipids by means of surface plasmon resonance. by German Stepanov, Oksana Gnedenko, Andrey Molnar, Alexis Ivanov, Yuri Vladimirov, Anatoly Osipov. FEBS letters. Read more related scholarly scientific articles and abstracts.

A sensor is described which utilizes the phenomenon of surface plasmon resonance to detect changes in refractive index of chemical or biochemical samples applied to a surface modified optical fiber. The sensor is constructed by polishing a short section of the lateral surface of an optical fiber to its evanescent field surrounding the fiber core. One or more thin films are applied to the polished section of the fiber to produce the sensing element. One of the films is the metal silver, which acts as the support for the surface plasmon. Under the proper conditions, TM polarized energy propagating in the fiber can be coupled to a surface plasmon electromagnetic mode on the metal film. This coupling depends on the wavelength, the nature of the fiber, the refractive index and thickness of the thin films applied to the fiber, and the refractive index of a chemical sample in contact with the modified surface. The fiber to plasmon coupling is seen as a large attenuation of the light reaching the distal ...

TY - GEN. T1 - Evaluation of an affinity-amplified immunoassay of graphene oxide using surface plasmon resonance biosensors. AU - Chiu, Nan-Fu. AU - Huang, Teng Yi. AU - Kuo, Chun Chuan. PY - 2015/1/1. Y1 - 2015/1/1. N2 - We describe a fundamental study on the plasmonic properties and advanced biosensing mechanisms of functionalized graphene. We discuss a specific design using modified carboxyl groups, which can modulate surface plasmon (SP) coupling and provide an advantage for their binding to the sensing layer with high-performance affinity in an immunological reaction. The functionalized graphene-based surface plasmon resonance (SPR) biosensors have three advantages: high performance, high sensitivity, and excellent molecular kinetic response. In the future, functionalized graphene sheets will make a unique contribution to photonic and SPR diagnosis devices. We wish to highlight the essential characteristics of functionalized graphene-based SPR biosensors to assist researchers in developing ...

TY - JOUR. T1 - Ultra-high sensitivity of the non-immunological affinity of graphene oxide-peptide-based surface plasmon resonance biosensors to detect human chorionic gonadotropin. AU - Chiu, Nan Fu. AU - Kuo, Chia Tzu. AU - Lin, Ting Li. AU - Chang, Chia Chen. AU - Chen, Chen Yu. PY - 2017/8/15. Y1 - 2017/8/15. N2 - Specific peptide aptamers can be used in place of expensive antibody proteins, and they are gaining increasing importance as sensing probes due to their potential in the development of non-immunological assays with high sensitivity, affinity and specificity for human chorionic gonadotropin (hCG) protein. We combined graphene oxide (GO) sheets with a specific peptide aptamer to create a novel, simple and label-free tool to detect abnormalities at an early stage of pregnancy, a GO-peptide-based surface plasmon resonance (SPR) biosensor. This is the first binding interface experiment to successfully demonstrate binding specificity in kinetic analysis biomechanics in peptide aptamers ...

TY - JOUR. T1 - An improved immunoassay for detection of saxitoxin by surface plasmon resonance biosensors. AU - Yakes, B.J.. AU - Prezioso, S.. AU - Haughey, S.A.. AU - Campbell, Katrina. AU - Elliott, Christopher. AU - DeGrasse, S.L.. PY - 2011/8. Y1 - 2011/8. N2 - Saxitoxin and its analogs, the causative agents of paralytic shellfish poisoning (PSP), are a worldwide threat to seafood safety. Effective monitoring of potentially contaminated fishing areas as well as screening of seafood samples is necessary to adequately protect the public. While many analytical methods exist for detecting paralytic shellfish toxins (PSTs), each technique has challenges associated with routine use. One recently developed method [1] that overcomes ethical or performance-related issues of other techniques is the surface plasmon resonance (SPR) bioassay. Notwithstanding the advantages of this method, much research remains in optimizing the sensor substrate and assay conditions to create a robust technique for ...

TY - JOUR. T1 - Application of surface plasmon coupled emission to study of muscle. AU - Borejdo, J.. AU - Gryczynski, Z.. AU - Calander, N.. AU - Muthu, P.. AU - Gryczynski, I.. N1 - Copyright: Copyright 2017 Elsevier B.V., All rights reserved.. PY - 2006/10. Y1 - 2006/10. N2 - Muscle contraction results from interactions between actin and myosin cross-bridges. Dynamics of this interaction may be quite different in contracting muscle than in vitro because of the molecular crowding. In addition, each cross-bridge of contracting muscle is in a different stage of its mechanochemical cycle, and so temporal measurements are time averages. To avoid complications related to crowding and averaging, it is necessary to follow time behavior of a single cross-bridge in muscle. To be able to do so, it is necessary to collect data from an extremely small volume (an attoliter, 10 -18 liter). We report here on a novel microscopic application of surface plasmon-coupled emission (SPCE), which provides such a ...

TY - JOUR. T1 - Surface plasmon resonance and emitted light properties of polystyrene sphere films. AU - Shinbo, Kazunari. AU - Miyabayashi, Syunsuke. AU - Yoshizawa, Kazushi. AU - Shimizu, Hidehiko. AU - Kato, Keizo. AU - Kaneko, Futao. AU - Tanaka, Masato. AU - Wakamatsu, Takashi. AU - Advincula, Rigoberto C.. PY - 2003. Y1 - 2003. N2 - Polystyrene sphere films were fabricated and the optical properties were investigated using surface plasmon spectroscopy (SPS) and emitted light due to reverse irradiation utilizing SPS Kretschmann configuration. The films were fabricated using sphere dispersed solution with various diameters from about 100 to 300 nm. The morphologies of the fabricated films were observed using atomic force microscopy and the sphere films had almost three layer structure. In SPS curve, large dip and shallow broad dip were observed at around 75° and 50°, respectively. The dips were considered to be due to the three layer structure and some defects in the film. Furthermore, ...

Diarrhoea caused by enterotoxigenic Escherichia coli is one of the leading causes of mortality in children under five years of age and is a great burden on developing countries. The major virulence factor of the bacterium is the heat-labile enterotoxin (LT), a close homologue of the cholera toxin. The toxins bind to carbohydrate receptors in the gastrointestinal tract, leading to toxin uptake and, ultimately, to severe diarrhoea. Previously, LT from human- and porcine-infecting ETEC (hLT and pLT, respectively) were shown to have different carbohydrate-binding specificities, in particular with respect to N-acetyllactosamine-terminating glycosphingolipids. Here, we probed eleven single-residue variants of the heat-labile enterotoxin with surface plasmon resonance spectroscopy and compared the data to the parent toxins. In addition we present a 1.45 Å crystal structure of pLTB in complex with branched Lacto-N-neohexaose (Galbeta4GlcNAcbeta6[Galbeta4GlcNAcbeta3]Galbeta4Glc). The largest difference in

An integrated surface plasmon resonance sensor Welcome to the Integrated Sensor System Training Program Website. Sensing is inherently a multidisciplinary field, and those who seek to advance and exploit knowledge in this area have a wide range of backgrounds, including physics, chemistry, mechanical and electrical engineering, biomedical engineering and medicine. Although often well-trained in their own domain of expertise they are not always ready to transfer their skills to industry. Most students have little exposure to other related research domains and do not appreciate that sensors are complex systems, requiring biorecognition or chemical recognition elements, sample delivery components (e.g. microfluidics), transducing elements, signal amplification, signal processing and packaging, and that a multidisciplinary approach is essential. Sensor systems must address specific markets and are subject to regulatory control. Students often also lack knowledge in the key techniques of micro or nano

Plural circuit selection using role reversing control inputs | SYSTEM AND METHOD OF DATA COMMUNICATION USING TRELLIS CODED MODULATION OR TURBO TRELLIS CODED MODULATION IN... | Multiple bit memory cells and methods for reading non-volatile data | Two-dimensional blazed MEMS grating | Surface plasmon resonance sensor having real-time referencing |

TY - JOUR. T1 - Asp271 is critical for substrate interaction with the surface binding site in β-agarase A from Zobellia galactanivorans. AU - Wilkens, Casper. AU - Tiwari, Manish K.. AU - Webb, Helen. AU - Jam, Murielle. AU - Czjzek, Mirjam. AU - Svensson, Birte. PY - 2019. Y1 - 2019. N2 - In the marine environment agar degradation is assured by bacteria that contain large agarolytic systems with enzymes acting in various endo- and exo-modes. Agarase A (AgaA) is an endo-glycoside hydrolase of family 16 considered to initiate degradation of agarose. Agaro-oligosaccharide binding at a unique surface binding site (SBS) in AgaA from Zobellia galactanivorans was investigated by computational methods in conjunction with a structure/sequence guided approach of site-directed mutagenesis probed by surface plasmon resonance binding analysis of agaro-oligosaccharides of DP 4-10. The crystal structure has shown that agaro-octaose interacts via H-bonds and aromatic stacking along 7 subsites (L through R) of ...

Fcgamma receptors (FcgammaRs) are expressed on all immunologically active cells. They bind the Fc portion of IgG, thereby triggering a range of immunological functions. We have used surface plasmon resonance to analyze the kinetic and thermodynamic properties of the interactions between the ectodomains of human low affinity FcgammaRs (FcgammaRIIa, FcgammaRIIb, and FcgammaRIIIb-NA2) and IgG1 or the Fc fragment of IgG1. All three receptors bind Fc or IgG with similarly low affinities (K(D) approximately 0.6-2.5 microm) and fast kinetics, suggesting that FcgammaR-mediated recognition of aggregated IgG and IgG-coated particles or cells is mechanistically similar to cell-cell recognition. Interestingly, the Fc receptors exhibit distinct thermodynamic properties. Whereas the binding of the FcgammaRIIa and FcgammaRIIb to Fc is driven by favorable entropic and enthalpic changes, the binding of FcgammaRIII is characterized by highly unfavorable entropic changes. Although the structural bases for these

TY - JOUR. T1 - Investigation of the mechanism of binding between internalin B and heparin using surface plasmon resonance. AU - Hrtska, Sybil C Lang. AU - Kemp, Melissa M.. AU - Muñoz, Eva M.. AU - Azizad, Omaira. AU - Banerjee, Mani. AU - Raposo, Catarina. AU - Kumaran, Jyothi. AU - Ghosh, Partho. AU - Linhardt, Robert J.. PY - 2007/3/13. Y1 - 2007/3/13. N2 - Listeria monocytogenes, a food-borne pathogen that infects immunocompromised patients, enters and proliferates within mammalian cells by taking advantage of host cell machinery. While entry into macrophages and other phagocytic cells occurs constitutively, intracellular invasion of nonphagocytic cells, such as epithelial and endothelial cells, occurs through induced phagocytosis. Invasion of these nonphagocytic cell types is under the control of the secreted L. monocytogenes protein internalin B (InlB), which directly associates with and activates the receptor tyrosine kinase Met. Activation of Met by InlB has previously been shown to be ...

Biosensor technology is a powerful alternative to conventional techniques, harnessing the specificity and sensitivity of biological systems in small, low cost devices. Despite the promising biosensors developed in research laboratories, there are not many reports of applications in agricultural monitoring. The authors review biosensor technology and discuss the different bio-receptor systems and methods of transduction. The difference between a biosensor and a truly integrated biosensor system are defined and the main reasons for the slow technology transfer of biosensors to the marketplace are reported. Biosensor research and development has been directed mainly towards health care, environmental applications and the food industry. The most commercially important application is the hand-held glucose meter used by diaberics. The agricultural/veterinary testing market has seen a number of diagnostic tests but no true biosensor systems have made an impact. The need for fast, on-line and accurate ...

Nanoplasmonic sensors typically comprise arrangements of noble metal nanoparticles on a dielectric support. Thus they are intrinsically characterized by surface topography with corrugations at the 10-100 nm length scale. While irrelevant in some bio- and chemosensing applications, it is also to be expected that the surface topography significantly influences the interaction between solids, fluids, nanoparticles and (bio)molecules, and the nanoplasmonic sensor surface. To address this issue, we present a wafer-scale nanolithography-based fabrication approach for high-temperature compatible, chemically inert and topographically flat and laterally homogeneous nanoplasmonic sensor chips. We demonstrate their sensing performance on three different examples, for which we also carry out a direct comparison with a traditional nanoplasmonic sensor with representative surface corrugation. Specifically, we (i) quantify the film-thickness dependence of the glass transition temperature in poly(methyl metacrylate)

This paper reports the fabrication and testing of two configurations of optical sensor systems based on Surface Plasmon Resonance (SPR) at the interface of a liquid sample and sandwiched structures realized starting from the exposed core of a Plastic Optical Fiber (POF). The proposed geometries have proven to be suitable for measuring the refractive indexes of liquids whose refractive index falls around 1.35. Furthermore, the proposed sensing head, being low cost and relatively easy to realize, may be very attractive for biosensor implementation.

Angiopoietin-like 4 (ANGPTL4) is involved in angiogenesis and lipid metabolism. It is secreted by liver and adipose tissues and cleaved to generate circulating coiled-coil domain (CCD) and fibrinogen-like domain (FLD) fragments. The full-length ANGPTL4 produced by hypoxic endothelial cells interacts with the extracellular matrix (ECM). The ECM-bound and soluble forms of ANGPTL4 have antiangiogenic properties. We carried out a structure-function analysis to investigate the regulation of ANGPTL4 bioactivity in endothelial cells. We found that the recombinant CCD binds to the ECM, whereas the FLD is released into the medium. The CCD, like the full-length ANGPTL4, binds to heparan and dermatan sulfates in surface plasmon resonance assays and inhibits endothelial cell adhesion, motility, and tubule-like formation. In endothelial cells, ANGPTL4 is processed in the secretion medium after release from the ECM. This processing is altered by the proprotein convertases inhibitor alpha1-PDX and abolished by the

The purpose of this work was to study the effect of various process and formulation parameters on size and shapes of silver nanoparticles (AgNPs) based on surface plasmon resonance (SPR). AgNPs were prepared by chemical reduction using formaldehyde (HCHO) as reducing agent and capped by polyethylene glycol (PEG). Effect of several processing variables including the concentration and volume of capping agent and reaction time is reported. The size of monodispersed nanoparticles was between 30-100 nm and was stable for three months at both room temperature and 4°C ...

A novel biosensing approach for the label-free detection of nucleic acid sequences of short and large lengths has been implemented, with special emphasis on targeting RNA sequences with secondary structures. The approach is based on selecting 8-aminoadenine-modified parallel-stranded DNA tail-clamps as affinity bioreceptors. These receptors have the ability of creating a stable triplex-stranded helix at neutral pH upon hybridization with the nucleic acid target. A surface plasmon resonance biosensor has been used for the detection. With this strategy, we have detected short DNA sequences (32-mer) and purified RNA (103-mer) at the femtomol level in a few minutes in an easy and level-free way. This approach is particularly suitable for the detection of RNA molecules with predicted secondary structures, reaching a limit of detection of 50fmol without any label or amplification steps. Our methodology has shown a marked enhancement for the detection (18 for short DNA and 54 for RNA), when compared ...

OpenPlex, Horiba Scientifics redesigned manual label-free SPRi-Lab+ system, uses surface plasmon resonance imaging (SPRi) for real-time analysi

A Rutgers-led team has created better biosensor technology that may help lead to safe stem cell therapies for treating Alzheimers and Parkinsons diseases and other neurological disorders. The technology, which features a unique graphene and gold-based platform and high-tech imaging, monitors the fate of stem cells by detecting genetic material (RNA) involved in turning such cells into brain cells (neurons), according to a study in the journal Nano Letters.

Nanoplasmonics has raised much concern on tailoring the strong optical fields near noble metal nanostructures. In particular, surface-enhanced Raman Scattering (SERS) can take the full benefits of nanoplasmonics for providing one of the most highly sensitive biochemical sensing techniques. This sensitivity is used to identify biochemical molecules even at single molecule level. This technique does not require fluorescent labeling. For decades, thousands of plasmonic nanoparticles or nanostructures mounted on substrates have been reported for plasmonics-driven SERS. However, previous work overlooks consideration of the quantitative investigation between plasmon resonance and SERS signals. This oversight has been due to available methodology.. Universal correlations between plasmon resonance and SERS has recently been described by the research of Ki-Hun Jeong (see, Kang et al.1) in Journal Advanced Materials - This observation was successfully enabled by deformable nanoplasmonic membrane, i.e., ...

The αβ T-cell coreceptor CD4 enhances immune responses more than 1 million-fold in some assays, and yet the affinity of CD4 for its ligand, peptide-major histocompatibility class II (pMHC II) on antigen-presenting cells, is so weak that it was previously unquantifiable. Here, we report that a soluble form of CD4 failed to bind detectably to pMHC II in surface plasmon resonance-based assays, establishing a new upper limit for the solution affinity at 2.5 mM. However, when presented multivalently on magnetic beads, soluble CD4 bound pMHC II-expressing B cells, confirming that it is active and allowing mapping of the native coreceptor binding site on pMHC II. Whereas binding was undetectable in solution, the affinity of the CD4/pMHC II interaction could be measured in 2D using CD4- and adhesion molecule-functionalized, supported lipid bilayers, yielding a 2D Kd of ∼5,000 molecules/μm(2) This value is two to three orders of magnitude higher than previously measured 2D Kd values for interacting

The obligate human pathogen Neisseria gonorrhoeae is responsible for the widespread sexually transmitted disease gonorrhoea, which in rare cases also leads to the development of disseminated gonococcal infection (DGI). DGI is mediated by PorBIA-expressing bacteria that invade host cells under low phosphate condition by interaction with the scavenger receptor-1 (SREC-I) expressed on the surface of endothelial cells. The interaction of PorBIA and SREC-I was analysed using different in vitro approaches, including surface plasmon resonance experiments that revealed a direct phosphate-independent high affinity interaction of SREC-I to PorBIA. However, the same binding affinity was also found for the other allele PorBIB, which indicates unspecific binding and suggests that the applied methods were unsuitable for this interaction analysis. Since N. gonorrhoeae was recently classified as a super-bug due to a rising number of antibiotic-resistant strains, this study aimed to discover inhibitors against ...

Generally, an immunoaffinity SPR biosensor detects a target analyte in a sample through highly selective adsorption by using the antigen–antibody interaction. For improving the sensitivity, various kinds of particles have been added to the already bound analytes on the SPR biosensor (sandwich assay). In this work, signal amplification was demonstrated by the expression of the IgG-binding Z-domain of protein A on the outer membrane of Escherichia coli via Autodisplay. The amount of Z-domain of protein A expressed on the outer membrane was calculated to be 280,000 molecules per cell. In addition, the IgGbinding ability of the expressed proteinwas characterized using FACS analysis. The signal amplification of the SPR biosensor was performed in the sandwich assay format using a model of horseradish peroxidase (HRP); the limit of detectionwas determined to be significantly improved from1 g/ml to 1 ng/ml. Finally, myoglobin analysis was demonstrated for the medical diagnosis of cardiac ...

Analysis of biological components is central in bioprocess monitoring, process control, product quality control and cell based toxicity assaying. One of these themes that is pursued in this thesis is the use of biosensors for monitoring of molecular markers, exploiting the natural selectivity of biomolecules. Another is the use of glycoconjugates to monitor the activity of biomolecules in a flu vaccine process is studied and were the sensor is based on the concept of weak affinity giving fast response time for the sensor.. A third theme is monitoring of cell cultures used for toxicity testing different protein markers is of interest.. When developing biosensor surfaces for new antigens commercial preparations of antibodies are often used. In this work we have chosen to look at lactate dehydrogenase (LDH) and describe the preparation and characterisation of antibody used in biosensor surface development.. The design of a sensor surface is important for the characteristics of a sensor. By binding ...

In order to overcome the sensitivity limitation of SPR, nanoparticle-coupled SPR biosensors have explored since nanoparticles may significantly enhance the sensitivity by 1-2 orders of magnitude. Although the nanoparticle conjugated method contributes to the enhancement of the sensitivity, it does not take an advantage of SPR from the viewpoint of label-free detection. Herein we demonstrate the sensitivity enhancement with Au nanoparticles coupled- SPR immuno-sensor chip on which the specific size and surface density of the particles controlled as a label-free detection system. Au nanopariticles were synthesized and selected with a specific size. Surface density of immobilized 30 nm Au nanoparticles on bare Au film was estimated as 1x109 ea/cm2 using atomic force microscopy. With systematic control of the size of the Au nanoparticle and thickness of the bare Au film, it was found that 30 nm Au particles on 50 nm thick Au film demonstrated the largest resonance angle shift for surface reaction on the

TY - JOUR. T1 - Toward surface plasmon polariton quantum-state tomography. AU - Dominguez, D.. AU - Regan, C. J.. AU - Bernussi, A. A.. AU - Grave De Peralta, L.. PY - 2013/2/21. Y1 - 2013/2/21. N2 - We report the direct excitation and detection of single-photon surface plasmon polariton (SPP) using a SPP tomography arrangement. Temporally spaced photons produced by spontaneous parametric downconversion were used to excite single-photon SPPs. The quantum statistics of the leakage radiation was studied using a Hanbury-Brown Twiss correlator arrangement. We observed a violation of the second order coherence test indicating leakage of temporally spaced photons. This demonstrates that leakage radiation associated with SPPs excited by single photons is composed of temporally spaced photons. Reaching the quantum regime of SPP tomography opens the door for further advances in SPP quantum state determination using SPP tomography.. AB - We report the direct excitation and detection of single-photon ...

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International Journal of Electrochemistry is a peer-reviewed, Open Access journal that publishes original research articles as well as review articles that further our understanding of fundamental electrochemical processes, describe new electrochemical techniques, apply electrochemistry in analytical determination, or apply electrochemistry for chemical reactivity.

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Get this from a library! Narrow plasmon resonances in hybrid systems. [Philip A Thomas] -- Advances in understanding the interactions between light and subwavelength materials have enabled the author and his collaborators to tailor unique optical responses at the nanoscale. In particular, ...

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Mentors: Berron, Hastings. Surface-plasmon resonance (SPR) sensing is a widely used optical technique for detecting and analyzing biochemical interactions. It has found applications in diverse fields such as medical diagnostics, drug discovery, and environmental monitoring. A key challenge for SPR is maximizing sensitivity to a target analyte while minimizing response to interfering species. Dr. Hastings group has developed several SPR sensors that use optical methods to distinguish specific and non-specific interactions. Dr. Berrons group has developed stable, low-density self-assembled monolayers that are ideal for functionalizing the gold surfaces common to SPR sensors. The tunable density of exposed functional groups should allow optimization of the interaction with a chosen target, while suppressing non-specific protein binding. In addition, the SPR technique itself will increase our understanding of the kinetics of protein adsorption on low-density monolayers. Students working on this ...

TY - JOUR. T1 - The interaction of serum albumin with cholesterol containing lipid vesicles. AU - Meierhofer, T. AU - van den Elsen, J M H. AU - Cameron, Petra J. AU - Munoz-Berbel, X. AU - Jenkins, A T A. PY - 2010/1. Y1 - 2010/1. N2 - In this paper, the interaction of both human blood serum (the primary fraction of which is serum albumin) and pure human serum albumin (HSA) with surface immobilised lipid vesicles was measured by combined Surface Plasmon Resonance (SPR) and Surface Plasmon enhanced Fluorescence (SPEFS), and fluorescence microscopy. It was found that both blood serum and HSA showed specific binding to vesicles which contained cholesterol, resulting in increased membrane permeability and release of encapsulated fluorescent dye. This effect was not seen with heat inactivated blood serum, heat inactivated HSA or in vesicles not containing cholesterol. These results suggest that HSA may have a physiological role over and beyond that of fatty acid carrier, possibly acting to regulate ...

Biomolecular interaction analysis (BIA) using SPR (surface plasmon resonance) biosensors is now utilised increasingly in nearly all phases of drug development. The BIA system consists out of a light source emitting near infrared light, a sensor microchip, an automated liquid handling system with constant flow and a diode array position-sensitive detector. One of the two interacting partners (referred to as the ligand) is immobilized on the sensor surface. The other binding partner, called the analyte, is directed over the surface in a constant flow system allowing to monitor the interaction of the binding partners in real time ...

The production of botulinum neurotoxin A (BoNT/A) for therapeutic and cosmetic applications requires precise determination of batch potency, and the enzymatic activity of BoNT/A light chain is a crucial index that can be measured in vitro. We previously established a SNAP-25 chip-based assay using surface plasmon resonance (SPR) that is more sensitive than the standard mouse bioassay for the quantification of BoNT/A activity. We have now adapted this procedure for pharmaceutical preparations. The optimized SPR assay allowed multiple measurements on a single chip, including the kinetics of substrate cleavage. The activity of five different batches of a pharmaceutical BoNT/A preparation was determined in a blind study by SPR and found to be in agreement with data from the in vivo mouse lethality assay. Biosensor detection of specific proteolytic products has the potential to accurately monitor the activity of pharmaceutical BoNT/A preparations, and a single chip can be used to assay more than 100 ...

Profacgen provides One-Stop-Service on protein-protein interaction analysis, including Yeast two-hybrid, Pull-downs and Surface Plasmon Resonance (SPR) assay etc., to facilitate your scientific research. Our service can be tailored according to your specific requirements.

Our laboratory improves magnetic resonance technology and spectroscopy for biomolecular structure determination relevant to HIV cure research. Solid state nuclear magnetic resonance (NMR) is exquisitely suited to probe atomic level structural detail of biomolecules within intact human cells. However, the small nuclear magnetic moments that yield narrow resonances also result in very low inherent sensitivity in NMR. Dynamic Nuclear Polarization (DNP) is a powerful combined electron paramagnetic resonance (EPR) and NMR technique that transfers the strong polarization from unpaired electron spins to nuclear spins to boost NMR sensitivity. In our DNP experiments, we employ frequency agile gyrotrons, and extreme cryogenic sample cooling to increase the sensitivity of solid state NMR experiments up to a factor of 20,000. This tremendous gain in sensitivity results in acquiring data 400 million times faster than conventional NMR experiments and will have a profound impact on magnetic resonance ...

Waltham, MA, January 2011 - Nova Biomedical today announced that, in response to rapid growth in its diabetes and whole blood point-of-care testing products business, it has purchased an additional 80,000 square-foot manufacturing/warehouse facility in Billerica, MA. According to Lou Borrelli, Nova Biomedical CFO, This additional state of the art manufacturing facility will ensure that our manufacturing capabilities keep pace with the increasing demand for our StatStrip Hospital Glucose products as well as our Nova Max consumer diabetes products.. One of the main drivers for Novas strong growth is the rapid adoption of its StatStrip Hospital Glucose Monitoring System. Since its inception just four years ago, StatStrip has become the fastest growing hospital glucose meter in the world. StatStrip uses a novel glucose test strip technology that measures hematocrit and other common interferences such as maltose, galactose, xylose, acetaminophen, ascorbic acid and oxygen, and eliminates erroneous ...

The most rapid and reliable way of detecting HIV is to search for the HIV genetic material directly in blood, using a process called PCR (polymerase chain reaction). This has the advantage of not needing to wait for such a long time after exposure, being used after only 3 days. Traditionally this process, known as molecular diagnostics, has been performed in a laboratory by trained personnel. Recent technological advances have however brought the possibility of conducting molecular diagnostics out of the laboratory and next to the patient at the point-of-care ...