Preparation of Molecular Sentinel Based Sers Sensor for Hepatitis C Virus

Abstract

Construction of a rapid, cost-effective and label free biosensor is important issue for public health. In this study, it has been developed a sensitive, selective and simple biosensor for the detection of hepatitis C virus (HCV) DNA. For this purpose, firstly, superparamagneticgold nanoparticles were prepared by simple citrate reduction method and used as surfaceenhanced Raman spectroscopy (SERS) substrate. Then, Raman labelled hairpin DNA(molecular sentinel, MS) was covalently bound on the gold shell by means of gold-sulfurinteraction. After addition the complementary DNA (target HCV DNA), the hairpinstructure was changed closed state (stem-loop configuration) to open state (hybridizationconfiguration). As a result, the Raman label was located far away from the surface andreduced the SERS intensity. A good relationship was obtained between the decreasing ofthe SERS intensity and the target DNA concentration (0-50 pM) and the limit of detectionwas found to be 0.1 pM. The sensing method only consists of a single hybridization andwashing procedure after hybridization and centrifuge step can be omitted. It is believed thatthe prepared biosensor could be a powerful diagnostic tool for HCV detection.