CsPbBr3 perovskite quantum dots/ZnO inverse opal electrodes: photoelectrochemical sensing for dihydronicotinamide adenine dinucleotide under visible irradiation.

All-inorganic perovskite quantum dots (PQDs) have attracted tremendous attention due to their extraordinary optical properties, especially CsPbBr₃ QDs with their high stability and photoluminescence efficiency. However, studies investigating the biosensing capabilities of PQDs are still limited. In this work, we designed a visible -light-triggered photoelectrochemical (PEC) sensor based on CsPbBr₃ QDs for the first time. The immobilized three-dimensional (3D) ZnO inverse opal photonic crystals (IOPCs) were applied to dihydronicotinamide adenine dinucleotide (NADH) sensing. It was found that the CsPbBr₃ QDs, as a photoactive material in a PEC sensor, can expand the photocurrent response of the PEC sensor to the visible region, as well as boost its conductivity. This PEC sensor based on a ZnO/CsPbBr₃ electrode demonstrates sensitive detection of NADH in phosphate buffer saline solution and serum, with a good linear range from 0.1 μM to 250 μM and a low detection limit of 0.010 μM. Our strategy offers a new approach to perovskite QD-based PEC sensing, which could be more sensitive and convenient for clinical analysis. [ABSTRACT FROM AUTHOR]