Magnet-assisted electrochemical immunosensor based on surface-clean Pd-Au nanosheets for sensitive detection of SARS-CoV-2 spike protein

Jialin Zhao; Fu Zhao; Haolin Li; Youlin Xiong; Shuangfei Cai; Chen Wang; Yunfa Chen; Ning Han; Rong Yang

doi:10.1016/j.electacta.2021.139766

Magnet-assisted electrochemical immunosensor based on surface-clean Pd-Au nanosheets for sensitive detection of SARS-CoV-2 spike protein

Electrochim Acta. 2022 Feb 1:404:139766. doi: 10.1016/j.electacta.2021.139766. Epub 2021 Dec 23.

Authors

Jialin Zhao^{1

2}, Fu Zhao¹, Haolin Li^{1

2}, Youlin Xiong¹, Shuangfei Cai¹, Chen Wang¹, Yunfa Chen³, Ning Han³, Rong Yang^{1

2}

Affiliations

¹ CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Center of Materials Science and Optoelectronics Engineering, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, University of Chinese Academy of Sciences, No.11 ZhongGuanCun BeiYiTiao, Beijing 100190, China.
² Sino-Danish College, Sino-Danish Center for Education and Research, University of Chinese Academy of Sciences, Beijing 100049, China.
³ State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China.

Abstract

Tracking and monitoring of low concentrations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can effectively control asymptomatic transmission of current coronavirus disease 2019 (COVID-19) in the early stages of infection. Here, we highlight an electrochemical immunosensor for sensitive detection of SARS-CoV-2 antigen marker spike protein. The surface-clean Pd-Au nanosheets as a substrate for efficient sensing and signal output have been synthesized. The morphology, chemical states and excellent stable electrochemical properties of this surface-clean heterostructures have been studied. Functionalized superparamagnetic nanoparticles (MNPs) were introduced as sample separators and signal amplifiers. This biosensor was tested in phosphate buffered saline (PBS) and nasopharyngeal samples. The results showed that the sensor has a wide linear dynamic range (0.01 ng mL^-1 to 1000 ng mL^-1) with a low detection limit (0.0072 ng mL^-1), which achieved stable and sensitive detection of the spike protein. Therefore, this immunosensing method provides a promising electrochemical measurement tool, which can furnish ideas for early screening and the reasonable optimization of detection methods of SARS-CoV-2.

Keywords: Differential pulse voltammetry; Immunosensor; Pd-Au nanosheets; SARS-CoV-2 spike protein.