Photoelectrochemical biosensor for Coxsackievirus B3 detection with recombinase polymerase amplification coupled with ZnSeNSs/AuNPs/BNNSs modified electrode

Abstract Coxsackievirus B3 (CVB3), a member of the genus Enterovirus, has high risks for incidence and mortality. Developing speedy and sensitive molecular diagnostics for CVB3 detection is challenging. Herein, a novel highly sensitive photoelectrochemical (PEC) biosensor based on nanocomposite (ZnSeNSs/AuNPs/BNNSs) modified electrode was fabricated. This biosensor relied on reverse transcription of CVB3 RNA and the rapid isothermal amplication by recombinase polymerase amplification (RPA). The amplified product was identified and linked to photoelectrode. Then biotin on the amplified product was connected to strepavidin-alkaline phosphatase (SA-ALP). The alkaline phosphatase catalyzed the hydrolysis of substrate 4-aminophenylphosphate monosodium (4-APP) to generate free 4-aminophenol which was a electron donor. An enhancing PEC signal was obtained. Therefore, a relationship between photocurrent response and CVB3 concentration was established. Under the optimal conditions, this PEC biosensor displayed a liner photocurrent response in the range of 0.1 fM ∼ 100 fM with a low detection limit of 30 aM. Furthermore, this strategy with satisfactory stability and selectivity provides an innovative way for CVB3 detection and lays a foundation for the research of portable devices for clinical sample processing and analysis in the further.