Search results for "SURFACE PLASMON"
showing 10 items of 393 documents
Stamping of monomeric SAMs as a route to structured crystallization templates: patterned titania films.
2000
Gold-coated glass slides have be patterned by using self-assembled monolayers (SAM) of alkane thiols. Through the use of a special thiol terminated with a styrene monomer, microstructures of 5 to 10 microm width and 70 A height have been formed on the surface by graft polymerization of styrene. These patterned gold slides have then been used to template the precipitation of thin titania films from ethanolic solutions of titanium isopropoxide to create microstructured architectures in the film. Plasmon resonance spectra have established the presence of different steps in the process and have been used to follow the kinetics of the precipitation of titania on the surface. The structured TiO2 …
Synthesis of rod-shaped gold nanorattles with improved plasmon sensitivity and catalytic activity.
2009
We prepared rod-shaped gold nanorattles solid gold nanorods surrounded by a thin gold shell using a galvanic replacement process starting with silver-coated gold nanorods. These structures are very promising candidates for catalytic applications and optimized plasmon sensors. They combine the advantages of rods (low plasmon resonance frequency, large polarizability, small damping) with the high surface area of hollow structures. The plasmon sensitivity to changes in the dielectric environment is up to 50% higher for gold nanorattles compared to gold nanorods with the same resonance frequency and 6x higher than for plasmons in spherical gold nanoparticles. The catalytic activity measured for…
Characterization of the interaction between Actinin-Associated LIM Protein (ALP) and the rod domain of α-actinin
2009
Abstract Background The PDZ-LIM proteins are a family of signalling adaptors that interact with the actin cross-linking protein, α-actinin, via their PDZ domains or via internal regions between the PDZ and LIM domains. Three of the PDZ-LIM proteins have a conserved 26-residue ZM motif in the internal region, but the structure of the internal region is unknown. Results In this study, using circular dichroism and nuclear magnetic resonance (NMR), we showed that the ALP internal region (residues 107–273) was largely unfolded in solution, but was able to interact with the α-actinin rod domain in vitro, and to co-localize with α-actinin on stress fibres in vivo. NMR analysis revealed that the ti…
Biosensor-based kinetic and thermodynamic characterization of opioids interaction with human μ-opioid receptor.
2019
Development of opioid analgesics with minimal side effects requires substantial knowledge on structure-kinetic and -thermodynamic relationship of opioid-receptor interactions. Here, combined kinetics and thermodynamics of opioid agonist binding to human μ-opioid receptor (h-μOR) was investigated using real-time label-free surface plasmon resonance (SPR)-based method. The N-terminal end truncated and C-terminal 6His-tagged h-μOR was constructed and expressed in E. coli. Receptor was purified, detergent-solubilized and characterized by circular dichroism. The uniform immobilization of h-μOR on Ni-NTA chips was achieved using hybrid capture-coupling approach followed by reconstitution in lipid…
Novel biosensor-based analytic device for the detection of anti-double-stranded DNA antibodies.
2007
AbstractBackground: Patients with systemic lupus erythematosus (SLE) develop a wide variety of serologic manifestations, including double-stranded DNA autoantibodies (anti-dsDNA). The determination of the potentially pathogenic autoantibodies is diagnostically relevant.Methods: We developed a novel surface plasmon resonance (SPR) biosensor chip for studies of dsDNA and anti-dsDNA binding. A synthetic oligonucleotide was coupled to biotinylated human transferrin, hybridized with the complementary antistrand, and ligated with a human recombinant dsDNA fragment 233 bp in length. After surface immobilization of this antigenic construct, diluted sera from SLE patients and healthy donors were ana…
Precise mapping of the Goodpasture epitope(s) using phage display, site-directed mutagenesis, and surface plasmon resonance.
2013
Goodpasture disease is an autoimmune disorder mediated by circulating autoantibodies against the noncollagenous-1 (NC1) domain of the alpha 3 chain of type IV collagen (alpha 3(IV)NC1). The structure of Goodpasture epitope(s) has been previously mapped into two main binding regions (E-A and E-B) of the alpha 3(IV)NC1 domain using a residue mutation approach on the highly related alpha 1(IV)NC1 domain. Here we combined phage display and surface plasmon resonance technology to more precisely localize the pathogenic binding sites. Peptides mimicking the Goodpasture epitope(s) were used to identify residues involved in autoantibody binding and found involvement of eight residues previously unre…
Localized Surface Plasmon Resonance in Colloidal Copper Sulphide (Cu2-xS, x = 0 ≤ x < 1) Nanocrystals and Its Applications
2021
Colloidally prepared copper sulphide (Cu2-xS) nanocrystals are possessing superior structural and optical properties owing to the presence of copper vacancies. The application of colloidal Cu2-xS nanocrystals are critically analysed for several optoelectronic applications. Furthermore, colloidally prepared Cu2-xS nanocrystals undergo facile process such as cation exchange, additives induced structural modifications etc. Therefore, it is important to evaluate the optical properties of these nanomaterials in order to apply them for future optoelectronic applications. Out of other properties, localized surface plasmon resonance (LSPR) by controlling composition of the Cu2-xS nanocrystals is in…
Nanomaterials and new biorecognition molecules based surface plasmon resonance biosensors for mycotoxin detection
2019
Mycotoxins are highly toxic secondary metabolites, which may contaminate many types of food and feeds. These toxins have serious health risks for both human and animals. One of the effective ways to prevent food contamination and protect people against mycotoxins is based on timely detection. Several methods like enzyme-linked immunosorbent assay and affinity chromatography are commercially available for this purpose. Nevertheless, sensitive, fast, simple, low-cost, and portable devices are absolutely required for a fast point-of care information and making decisions. Application of biosensors appears to be a possible technique to meet this need for mycotoxins analyze. The present study has…
Dipole surface plasmon in K+N clusters
1992
Abstract The technique of sum rules has been used to investigate the dipole surface plasmon for K + N clusters within a Density Functional Theory and the spherical jellium model. The role played by non-local effects is discussed comparing the results obtained from different functionals. Band-structure and core-polarization effects have been phenomenologically included in the calculation by means of an electron effective mass and a dielectric constant. Comparison with recent experimental data is presented.
Plasmon de surface de particules métalliques toroïdales
2006
This thesis deals with the optical properties of small metal torii. A method of resolution of the equation of Laplace in toroidal coordinates is introduced and the radiative properties of the metal toric nanoparticules are studied within the electrostatic framework. The study on the eigenmodes spatial distribution suggests that metal nanotorus can carry a non-zero magnetic dipole moment at optical frequencies. Analytical expressions for the extinction and scattering cross sections of the torus are also found and compared with numerical simulations and experimental results obtained with collaborations. The sensitivity of the plasmon frequency to the refraction index of the external medium an…