SERS-ELISA using silica-encapsulated Au core-satellite nanotags for sensitive detection of SARS-CoV-2

Qian Yu; Hoa Duc Trinh; Yeonji Lee; Taejoon Kang; Lingxin Chen; Sangwoon Yoon; Jaebum Choo

doi:10.1016/j.snb.2023.133521

SERS-ELISA using silica-encapsulated Au core-satellite nanotags for sensitive detection of SARS-CoV-2

Sens Actuators B Chem. 2023 May 1:382:133521. doi: 10.1016/j.snb.2023.133521. Epub 2023 Feb 14.

Authors

Qian Yu¹, Hoa Duc Trinh¹, Yeonji Lee¹, Taejoon Kang^{2

3}, Lingxin Chen⁴, Sangwoon Yoon¹, Jaebum Choo¹

Affiliations

¹ Department of Chemistry, Chung-Ang University, Seoul 06974, South Korea.
² Bionanotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, South Korea.
³ School of Pharmacy, Sungkyunkwan University, Suwon 16419, South Korea.
⁴ Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China.

Abstract

The sensitive detection of viruses is key to preventing the spread of infectious diseases. In this study, we develop a silica-encapsulated Au core-satellite (CS@SiO₂) nanotag, which produces a strong and reproducible surface-enhanced Raman scattering (SERS) signal. The combination of SERS from the CS@SiO₂ nanotags with enzyme-linked immunosorbent assay (ELISA) achieves a highly sensitive detection of SARS-CoV-2. The CS@SiO₂ nanotag is constructed by assembling 32 nm Au nanoparticles (AuNPs) on a 75 nm AuNP. Then the core-satellite particles are encapsulated with SiO₂ for facile surface modification and stability. The SERS-ELISA technique using the CS@SiO₂ nanotags provides a great sensitivity, yielding a detection limit of 8.81 PFU mL-1, which is 10 times better than conventional ELISA and 100 times better than lateral flow assay strip method. SERS-ELISA is applied to 30 SARS-CoV-2 clinical samples and achieved 100% and 55% sensitivities for 15 and 9 positive samples with cycle thresholds < 30 and > 30, respectively. This new CS@SiO₂-SERS-ELISA method is an innovative technique that can significantly reduce the false-negative diagnostic rate for SARS-CoV-2 and thereby contribute to overcoming the current pandemic crisis.

Keywords: Diagnostics; Infectious disease; SARS-CoV-2; SERS-ELISA; Surface-enhanced Raman scattering (SERS).