A photoelectrochemical biosensor for fibroblast-like synoviocyte cell using visible light-activated NCQDs sensitized-ZnO/CH3NH3PbI3 heterojunction

Based on ZnO nanorods (NRs)/CH 3 NH 3 PbI 3 /nitrogen-doped carbon quantum dots (NCQDs) nanocomposites , the highly sensitive detection of fibroblast-like synoviocyte (FLS) cell was realized by a photoelectrochemical (PEC) biosensor. ZnO/CH 3 NH 3 PbI 3 /NCQDs nanocomposites were exploited as the photo-to-electron generator to produce the signal. CH 3 NH 3 PbI 3 was spin-coated on ZnO surface after ZnO NRs grew on ITO electrode then by dropping on the modified electrode , NCQDs were diffused and adhered to the surface of ZnO and CH 3 NH 3 PbI 3 . In the presence of EDC/NHS, the combination of CH 3 NH 3 PbI 3 and NCQDs was achieved by the carboxyl groups (–COOH) and amino groups (–NH 2 ) in the preparation process. Furthermore, the capture probe of FLS cell, CD95 antibody, can be anchored by –COOH and –NH 2 groups through EDC/NHS. The specific recognition between the antibody capture probes and cell targets gained high-sensitive detection for FLS cell for the first time. The developed biosensor showed a wide linear range from 1.0×10 4   cell/mL to 10   cell/mL and a low detection limit of 2   cell/mL. This kind of biosensor would provide a novel detection strategy for FLS cell.