Self-powered cathodic photoelectrochemical aptasensor based on in situ-synthesized CuO-Cu 2 O nanowire array for detecting prostate-specific antigen.

A facile and sensitive self-powered cathodic photoelectrochemical (PEC) aptasensor is reported for the detection of prostate-specific antigen (PSA) based on CuO-Cu ₂ O nanowire array grown on Cu mesh (CuO-Cu ₂ O NWA/CM) as electrode. The mixed narrow band gaps of the CuO-Cu ₂ O heterostructure ensured its wide absorption band, effective electron/hole separation, and high photocatalytic activity in the visible region. In addition, nanowires directly grown on the substrate provided high specific surface area and exposed abundant active sites, thus guaranteeing its high photocatalytic efficiency. Therefore, the self-powered sensor exhibited favorable analytical performance with fast response, wide linear ranges of 0.01 to 5 ng/mL and 5 to 100 ng/mL, an acceptable detection limit of 3 pg/mL, and reasonable selectivity and stability. The proposed CuO-Cu ₂ O NWA/CM can be considered a promising visible light-responsive photoactive material for fabrication of PEC aptasensor with high performance. Graphical abstract a Schematic illustration of construction process of PEC sensing platform based on the CuO-Cu ₂ O composite for PSA detection. b Schematic mechanism of the operating PEC system.