Electrochemical detection of SARS-CoV-2 based on copper nanoflower-triggered growth of electroactive polymers

• Published in: Analyst (London) Vol. 148; no. 15; pp. 3659 - 3665
• Main Authors: Lu, Ji, Zhou, Xiaotian, Li, Yi, Yu, Min, Fu, Siyuan, Qu, Zhiling, Li, Yanling, Miao, Jinfeng, Xu, Yuanyuan
• Format: Journal Article
• Published: 26.07.2023
• ISSN: 0003-2654; 1364-5528
• DOI: 10.1039/d3an00716b

SARS-CoV-2, the pathogen of COVID-19, has introduced massive confirmed cases and millions of deaths worldwide, which poses a serious public health threat. For the early diagnosis of COVID-19, we have constructed an electrochemical biosensor-combined magnetic separation system with copper nanoflower-triggered cascade signal amplification strategy. In the proposed system, magnetic beads were utilized to fabricate the recognition element for capturing the conserved sequence of SARS-CoV-2. As the copper ions source, oligonucleotides modified copper nanoflowers with special layered structure provide numerous catalysts for click chemistry reaction. When target sequence RdRP_SARSr-P2 appears, copper nanoflowers will be bound with magnetic beads, thus prompting the Cu( i )-catalyzed azide-alkyne cycloaddition reaction through the connection of the SARS-CoV-2 conserved sequence. Then, a large number of signal molecules FMMA can be grafted onto the modified electrode surface by electrochemically mediated atom-transfer radical polymerization to amplify the signal for the quantitative analysis of SARS-CoV-2. Under optimal conditions, a linear range from 0.1 to 10 3 nM with a detection limit of 33.83 pM is obtained. It provides a powerful tool for the diagnosis of COVID-19, which further benefits the early monitoring of other explosive infectious diseases effectively, thus guaranteeing public health safety. Cascade signal amplification triggered by copper nanoflowers and eATRP reaction ensures ultrasensitive detection. Fast on-site testing can be carried out without the need for large instruments and specialized laboratories.