A Split Organic Photophotochemical Transistor/Vision Sensing Platform Based on Mnz Composite and Zif-67/Cucoo Nanospheres for Ultra-Sensitive Detection of Cea

In this study, we have proposed a novel organic photophotochemical transistor (OPECT) biosensing platform based on the exceptional photoelectric performance of MIL-53(Fe) -NH2@ZnIn2S4 (MNZ) and the peroxidase enzyme (POD) activity of ZIF-67/Cu0.76Co2.24O4 (ZIF-67/CuCoO), achieving dual-mode detection of CEA. On the one hand, the Ab2- ZIF-67/CuCoO probe was immobilized on a 96-well plate by enzyme-linked immunosorbent assay. Because of its excellent POD activity, it accelerated the oxidation of 3,3,5,5-tetramethylbenzidine (TMB) by hydrogen peroxide to form different degrees of color reaction, and successfully realized the visual detection of different concentrations of CEA. On the other hand, as a part of OPECT biosensing, the oxidized form of TMB (oxTMB·) serves as a consumptive agents of the electron donor AA, it can cause the change of MNZ heterojunction regulated poly (ethylenedioxythiophene): poly (styrene sulfonate) (PEDOT: PSS) organic transistor, leading to a decrease in the channel current, and can be used for OPECT biosensing of carcinoembryonic antigen (CEA). The combination of nanobiocatalysts and the OPECT system has expanded their application in the field of biological analysis. This integration demonstrates excellent detection performance for CEA, with a detection limit as low as 3.24 fg mL-1. The OPECT platform provided by this study presents prospective applications for clinical detection of nucleic acids, proteins, and other tumor markers.