SERS/EC Dual-Mode Sensing System for the Assay of SARS-CoV-2 RNA by Using Single Gold Nanowires as a Platform

The continuous spread and infection of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) worldwide has brought a great impact on people’s lives and health and become a serious public health problem. In this contribution, a surface-enhanced Raman scattering/electrochemical (SERS/EC) dual-mode sensing system using single Au nanowires (Au NWs) as a platform is proposed for detecting the SARS-CoV-2 RNA with excellent sensitivity and selectivity. The Au NWs modified with bimetallic NPs can significantly increase the SERS/EC signals, and the presence of the SARS-CoV-2 RNA can produce significantly attenuated SERS/EC signals by shearing off the aptamer containing the signal molecules. In addition to its excellent specific recognition of the SARS-CoV-2 RNA and high sensitivity (detection limits of 1.02 pM by the SERS method and 0.21 pM by the EC method), this nanosensor has been successfully applied to samples with complex matrices and is expected to serve as a potential, sensitive, and reliable tool for virus screening and protein detection, especially for in vivo detection due to the small overall dimension of single Au NWs.