Electrochemiluminescence and photoelectrochemistry dual-signal immunosensor based on Ru(bpy)32+-functionalized MOF for prostate-specific antigen sensitive detection

A novel electrochemiluminescence (ECL) and photoelectrochemistry (PEC) dual-signal immunosensor for detection of prostate-specific antigen (PSA) is constructed based on Ru(bpy)32+/MOF (Ru-MOF) composite material. Ru-MOF film not only produces strong ECL signals coexisted with the K2S2O8 but also shows good PEC property under light. In order to obtain maximum quenching of ECL and PEC intensity, typical Cu2O-coated Pd shell-core-structured nanoparticles (Pd/Cu2O) as a quencher is introduced into the system. A signal-reduced sandwich immunosensing structure is constructed among the primary antibody Ab1 connected to the Ru/MOF modified electrode, PSA, and the secondary antibody Ab2 loaded with Pd/Cu2O. Excellent dual signals generated by Ru/MOF is quenched by quencher Pd/Cu2O. Thereby a ECL and PEC dual-signal immune sensor for PSA detection is successfully constructed. This immunosensor shows wide linearity ranges (5 pg mL−1 to 5 μg mL−1 for ECL, 5 ng mL−1 to 150 ng mL−1 for PEC) and low detection limits (1.783 pg mL−1 for ECL, 0.163 ng mL−1 for PEC), respectively. Moreover, this immunosensor also shows satisfactory detection ability on real samples. By this method, the advantages of PEC and ECL can be combined into one system. Thus, different detection modes can be chosen to achieve multi-method detection of individual sample according to actual requirements and improve the detection reliability. This strategy provides a new idea for construction of multi-signal response sensor with good perspective in PSA diagnosis.