Sensitive and high-throughput protein analysis based on CdS@g-C3N4 heterojunction-modified spatial-resolved rotatable electrode array

Abstract A general spatial-resolved photoelectrochemical (PEC) sensing platform for sensitive and high-throughput protein analysis was developed by integrating CdS@g-C3N4 heterojunction modified rotatable electrodes array with signal antibodies labeled Cu2O (Cu2O-Ab2) conjugates. The disk substrate containing eight spatial-resolved working electrodes array was fabricated using acid etching treatment method. After stepwise immobilizing CdS@g-C3N4, capture antibodies (Ab1), varied concentrations of target protein (prostate-specific antigen) and Cu2O-Ab2 conjugates on the corresponding sensing sites, the immunosensor array was prepared completely. Combining the high photoelectric conversion efficiency of the photoactive material with the effective signal probe, the immunosensor exhibits high sensitivity. The proposed spatial-resolved immunosensing platform shows a working range of 1.0 × 10-11 – 5.0 × 10-8 g mL−1 with a detection limit of 5.0 pg mL−1. The method provides a universal paradigm for near-simultaneously detection of multi-batch samples with good specificity and high sensitivity.