title: Strong improvements of localized surface plasmon resonance sensitivity by using Au/Ag bimetallic nanostructures modified with polydopamine films.
abstract: In the present work, the standard monometallic localized surface plasmon resonance (LSPR) biosensing sensitivity is highly improved when using a new system based on glass substrates modified with high-temperature annealed gold/silver bimetallic nanoparticles (Au/Ag bimetallic NPs) coated with polydopamine films before biomolecule specific immobilization. Thus, different zones of bimetallic NPs are spatially created onto a glass support thanks to a commercial transmission electron microscopy (TEM) grid marker in combination with two sequential evaporations of continuous films of gold (4 nm) and silver (2 nm) and followed by annealing at 500 °C for 8 h. By using the scanning electron microscopy (SEM), it is found that annealed Au/Ag bimetallic NPs have uniform size and shape distribution that exhibited a sharper well-defined LSPR resonant peak when compared with that of monometallic Au NPs and thereby contributing to an improved sensitivity in LSPR biosensor application. The controlled micropatterns consisting of bimetallic particles are used in the construction of LSPR biochips for high-throughput detection of different concentrations of a model antigen named bovine serum albumin (BSA) on a single glass sample, with a lower limit of detection of 0.01 ng/mL under the optimized conditions.
authors.affiliation: Laboratoire de Nanotechnologie et d'Instrumentation Optique and ‡Laboratoire des Systèmes Mécaniques et d'Ingénierie Simultanée, UMR-STMR CNRS 6279, Institute Charles Delaunay, Université de Technologie de Troyes , 12 Rue Marie Curie CS 42060, 10004 Troyes Cedex, France.
authors.forename: Kun
authors.initials: K
authors.lastname: Jia
authors.forename: Mohammad Y
authors.initials: MY
authors.lastname: Khaywah
authors.forename: Yugang
authors.initials: Y
authors.lastname: Li
authors.forename: Jean L
authors.initials: JL
authors.lastname: Bijeon
authors.forename: Pierre M
authors.initials: PM
authors.lastname: Adam
authors.forename: Régis
authors.initials: R
authors.lastname: Déturche
authors.forename: Bruno
authors.initials: B
authors.lastname: Guelorget
authors.forename: Manuel
authors.initials: M
authors.lastname: François
authors.forename: Guy
authors.initials: G
authors.lastname: Louarn
authors.forename: Rodica E
authors.initials: RE
authors.lastname: Ionescu