On May 3, 2022, the research paper entitled "Nanobody-based label-free photoelectro-chemical immunoassay for highly sensitive detection of SARS-CoV-2 spike protein" was published in the Analytica Chimica Acta by the team of Professor Li Henan of the School of Chemistry and Chemical Engineering of Jiangsu University and Novamab. Dr. Wan Yakun and Professor Li Helan of Novamab are the parallel correspondents. The intellectual property rights of relevant nanoantibodies belong to Novamab.

COVID-19 caused by SARS-CoV-2 is sweeping the world, and is still in Manyan, continuing to threaten public health. The main challenge of COVID-19 epidemic is the lack of rapid response and efficient methods to identify the pathogen of SARS-CoV-2 virus. For the needs of treatment strategies and protective measures, it is urgent to use fast and efficient diagnostic methods.

In this study, a label-free photoelectrochemical (PEC) immunosensor based on nanoantibody was prepared for rapid detection of SARS-CoV-2 spike protein, which has good sensitivity, stability, reproducibility and applicability. As a kind of small size and high stability antibody, nanoantibody is directly fixed with gold nanoparticles and titanium dioxide spheres through interaction. Due to the surface plasmon resonance effect of Au, the photoelectric performance of Au deposited titanium dioxide nanomaterials in the presence of electron donors is 8.5 times that of titanium dioxide. Based on the steric hindrance effect, the immune analysis platform has achieved a linear detection of 0.015~15000pg/mL, and the detection limit is as low as 5fg/mL. This study provides a new way to prepare immunosensors based on nanoantibodies, and opens the door of COVID-19 virus detection through a simple and rapid PEC immunoassay method.