Au-MPY/DTNB@SiO2 SERS nanoprobe for immunosorbent assay

Abstract

In this paper, we developed a biocompatible surface-enhanced Raman scattering (SERS) nanoprobe that employs 4-mercaptopyridine (MPY)/5,5-dithiobis(2-nitrobenzoic acid) (DTNB)-decorated gold aggregates embedded in silicon dioxide. This highly sensitive SERS nanoprobe was applied in immunoassays. Furthermore, we constructed a sandwich (silver-proteins-Au-MPY/DTNB@SiO2) model that contributes very strong electromagnetic (EM) fields. Compared with a single layer of the SERS-active substrate, the designed model exhibited highly sensitive detection capabilities. This method demonstrates considerable potential for ultrasensitive SERS immunoassay applications. In addition, the proposed silica protected gold nanoaggregates possess good biocompatibility with proteins. (C) 2016 Elsevier B.V. All rights reserved.