Ce3+/Ce4+ redox-driven oxidase-mimicking single-atom nanozyme for selective malathion detection through acid phosphatase-mediated cascade signaling.

Exploiting intrinsic Ce3+/Ce4+ redox cycling for H2O2-independent TMB oxidation, a cascade colorimetric platform was constructed in which malathion selectively inactivates acid phosphatase via covalent Ser-O-P phosphorylation, enabling naked-eye and instrument-free detection of organophosphate contamination in real water matrices with high selectivity and robustness.