Amplification-Free DNA Biosensing by Surface-Enhanced Raman Scattering Based on Au Nanobipyramids Decorated Ag Nanorod Array

Abstract

Virus identification has great significance to respond appropriately to pandemic disease threats. Therefore, an amplification-free DNA detection method based on surfaceenhanced Raman scattering (SERS) for severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) N gene was proposed. Herein, Au nanobipyramids (AuNBPs) are coupled with Ag Nanorod Array (AgNRA) to create plasmonic “hot spots” in the presence of target DNA, which enables a large density of Raman labels to experience an intense, spatially distributed electromagnetic field, ensures the highly sensitive DNA detection. Quantitative analysis was performed by monitoring the characteristic Raman peak intensity of Raman labels. The target DNA quantity in the range of 10 fM to 10 nM, and the limit of detection (LOD) was 3.16 fM. This approach exhibited good detection performance and is expected to be a potentially useful tool for virus detection.