Authors
Kun Jia, Mohammad Khayway, Yugang Li, Jean-Louis Bijeon, Pierre-Michel Adam, Régis Déturche, Bruno Guelorget, Manuel François, Guy Louarn, Rodica Eléna Ionescu,
Title
Strong improvements of LSPR sensitivity by using Au/Ag bi-metallic nanostructures modified with poly-dopamine films
In
ACS Applied Materials & Interfaces
Volume
6
Pages
219–227
Publisher
ACS
Year
2014
Publisher's URL
http://pubs.acs.org/doi/abs/10.1021/am403943q
Indexed by
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.
Affiliations
Offprint