“…For high sensitive and specific detection of SARS-CoV-2 RNA, the wildly-agreed gene fragment in the open reading frame 1 ab (ORF1ab) region with highly conserved viral nucleic acid sequences was selected as the target sequence ( Li et al, 2021 ; Udugama et al, 2020 ; Wang et al, 2021 ). Scheme 1 b illustrates the unlocking-mediated target recycling signal amplification strategy for SERS detection of SARS-CoV-2 RNA, which includes five parts, i.e., LPs, H2, SERS tags, SERS sensing chip and analyte.…”