Antibody- and aptamer-free SERS substrate for ultrasensitive and anti-interference detection of SARS-CoV-2 spike protein in untreated saliva

Hong Zhang; Chenggang Zhang; Zhaotong Wang; Wenwu Cao; Miao Yu; Ye Sun

doi:10.1016/j.bios.2023.115457

Antibody- and aptamer-free SERS substrate for ultrasensitive and anti-interference detection of SARS-CoV-2 spike protein in untreated saliva

Biosens Bioelectron. 2023 Oct 1:237:115457. doi: 10.1016/j.bios.2023.115457. Epub 2023 Jun 8.

Authors

Hong Zhang¹, Chenggang Zhang¹, Zhaotong Wang¹, Wenwu Cao¹, Miao Yu², Ye Sun³

Affiliations

¹ School of Instrumentation Science and Engineering, Harbin Institute of Technology, Harbin, 150001, Heilonɡjianɡ, PR China.
² State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, Heilonɡjianɡ, PR China. Electronic address: miaoyu_che@hit.edu.cn.
³ School of Instrumentation Science and Engineering, Harbin Institute of Technology, Harbin, 150001, Heilonɡjianɡ, PR China. Electronic address: sunye@hit.edu.cn.

Abstract

Sensitive and anti-interference detection of targeted signal(s) in body fluids is one of the paramount tasks in biosensing. Overcoming the complication and high cost of antibody/aptamer-modification, surface-enhanced Raman spectroscopy (SERS) based on antibody/aptamer-free (AAF) substrates has shown great promise, yet with rather limited detection sensitivity. Herein, we report ultrasensitive and anti-interference detection of SARS-CoV-2 spike protein in untreated saliva by an AAF SERS substrate, applying the evanescent field induced by the high-order waveguide modes of well-defined nanorods for SERS for the first time. A detection limit of 3.6 × 10^-17 M and 1.6 × 10^-16 M are obtained in phosphate buffered saline and untreated saliva, respectively; the detection limits are three orders of magnitude improved than the best records from AAF substrates. This work unlocks an exciting path to design AAF SERS substrates for ultrasensitive biosensing, not limited to detection of viral antigens.

Keywords: Antibody/aptamer-free; Biosensor; SARS-CoV-2 spike protein; SERS; Untreated saliva.

MeSH terms

Antibodies
Aptamers, Nucleotide* / chemistry
Biosensing Techniques* / methods
COVID-19* / diagnosis
Humans
Metal Nanoparticles* / chemistry
SARS-CoV-2
Saliva
Spectrum Analysis, Raman / methods
Spike Glycoprotein, Coronavirus

Substances

spike protein, SARS-CoV-2
Spike Glycoprotein, Coronavirus
Antibodies
Aptamers, Nucleotide