Macrophage-Inspired Degradation-Activation System Enables Ultrasensitive Multicolor Detection of Haloacetic Acids via Janus Perovskite Halide Exchange

Haloacetic acids (HAAs), as representative disinfection byproducts, have the potential hazards of teratogenesis, carcinogenesis, and mutagenesis. Herein, inspired by the scavenging physiology of macrophages and taking advantage of the unique properties of perovskites, we design a biomimetic integrated three-step workflow, named the macrophage-inspired degradation-activation system (MIDAS), for the detection of HAAs in aqueous samples. First, HAAs are “devoured” by methyl t-butyl ether (MTBE) from a sample. Then, ultraviolet C is utilized to induce the photolysis of MTBE and the dehalogenation of HAAs. Third, the photoinduced product, tertiary butyl haloalkane, can activate the vacancy defect-facilitated halide exchange of perovskites, generating multicolor fluorescent signals. The MIDAS realizes the rapid (<5 min), ultrasensitive (limit of detection: 30 and 15 ppb), and accurate (recovery: 95.2–109.4%) quantification of dichloroacetic acid and dibromoacetic acid in real water samples. Furthermore, a chemometrics-supported MIDAS portable platform is established for the visual semi-quantification of HAAs and the discrimination of binary mixed HAAs on site. The MIDAS-based strategy provides a highly efficient approach to trigger the perovskite halide exchange and shows the Midas touch-like ability in the fluorescent assay of HAAs in aqueous samples. To our knowledge, this is the first universal multicolor fluorimetry and the first application of perovskites for HAA detection.