The sensitive and precise assay of protein tyrosine phosphatase 1B (PTP1B) activity plays a considerable role in clinical diagnosis and cancer therapy. Herein, a photoelectrochemical (PEC)-colorimetric (CL) dual-mode biosensor based on magnetic Fe3O4 nanospheres and vinyl-functionalized covalent organic framework (COFV) with photoelectric property and light-responsive oxidase-mimetic activity was developed for PTP1B activity assay. Fe3O4 nanospheres modified with polydopamine (PDA) and chelated Ti4+ (Fe3O4@PDA-Ti4+) were synthesized by the self-polymerization of dopamine and the chelation reac...
