SERS detection of hepatitis B virus DNA in a temperature-responsive sandwich-hybridization assay

In this study, we report the design of a DNA sensor for the detection of a DNA sequence representative of the hepatitis B virus (HBV) based on a sandwich assay and surface-enhanced Raman scattering (SERS) measurement. The temperature-responsive hybrid silicon substrate was first prepared via immobilization of capture DNA strand at the surface of gold nanoparticles on the hybrid silicon substrate. A sandwich strategy was then applied for the detection of target DNA that brings a reporter DNA labeled with indocyanine green to the proximity of the surface, leading to high SERS signals. The temperature-responsive hybrid silicon substrate-based SERS platform can detect the remarkably lowest HBV DNA concentrations at ~0.44 fm at 25 °C and ~0.14 fm at 37 °C, respectively, which are comparable with the lowest HBV DNA concentration ever via other techniques. We expect this highly sensitive and robust hybrid silicon substrate-based SERS platform can be extended to detect other biomolecules and chemical species such as viruses, proteins, and small molecules without any labeling. Copyright © 2017 John Wiley & Sons, Ltd.