Atomically Dispersed Mn Boosting Photoelectrochemical SARS-CoV-2 Spike Protein Immunosensing on Carbon Nitride

ABSTRACT

The sudden outbreak of coronavirus disease (COVID-19) triggered by SARS-CoV-2 infection has created a terrifying situation around the world. The Spike protein of SARS-CoV-2 may act as an early biomarker for leading to receptor binding and virus entry. Therefore, controlling the spread of COVID-19 requires a low-cost, fast-response, and sensitive monitoring technique of spike protein. Herein, a photoelectrochemical (PEC) immunosensor for the detection of spike protein was constructed using the nanobody and an Mn (Ⅱ) modified graphitic carbon nitride (Mn/g-C3N4). The introduction of atomically dispersed Mn (Ⅱ) accelerates the effective transfer and separation of photogenerated electron-hole pairs, which significantly boosts PEC performance of g-C3N4, thereby improving the detection sensitivity. As a recognition site, nanobody can achieve high-affinity binding to the spike protein for detection. The linear detection range of the proposed PEC immunosensor was 75 fg mL–1 to 150 pg mL–1, and the limit of detection was calculated to be 1.22 fg mL–1. This stable and feasible PEC immunosensor is a promising diagnostic tool for sensitively detecting SARS-CoV-2 spike protein. Graphical