Plasmonic Annular Nanotrenches with 1 nm Nanogaps for Detection of SARS-CoV‑2 Using SERS-Based Immunoassay

• Published in: Nano letters Vol. 24; no. 14; pp. 4233 - 4240
• Main Authors: Lee, Sungwoo, Lee, Seonghyeon, Park, Woongkyu, Lee, Soohyun, Kwon, Sunwoo, Oh, Myeong Jin, Haddadnezhad, MohammadNavid, Jung, Insub, Kim, Bohyeon, Park, Jieun, Shin, Kyu Sung, Lee, Hyungdon, Yoo, Junsang, Kim, Won-Keun, Park, Sungho
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 10-04-2024
• Subjects: COVID-19 - diagnosis; Gold; Humans; Immunoassay - methods; Metal Nanoparticles; SARS-CoV-2; Spectrum Analysis, Raman - methods; Au nanoparticle; SARS-CoV-2; SERS; nanogap; immunoassay
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/acs.nanolett.4c00451

This study represents the synthesis of a novel class of nanoparticles denoted as annular Au nanotrenches (AANTs). AANTs are engineered to possess embedded, narrow circular nanogaps with dimensions of approximately 1 nm, facilitating near-field focusing for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) via a surface-enhanced Raman scattering (SERS)-based immunoassay. Notably, AANTs exhibited an exceedingly low limit of detection (LOD) of 1 fg/mL for SARS-CoV-2 spike glycoproteins, surpassing the commercially available enzyme-linked immunosorbent assay (ELISA) by 6 orders of magnitude (1 ng/mL from ELISA). To assess the real-world applicability, a study was conducted on 50 clinical samples using an SERS-based immunoassay with AANTs. The results revealed a sensitivity of 96% and a selectivity of 100%, demonstrating the significantly enhanced sensing capabilities of the proposed approach in comparison to ELISA and commercial lateral flow assay kits.