Harnessing the pyrophosphate-triggered disassembly of MIL-88B(Fe) for in situ dual-signal generation and reliable acetamiprid detection.

This work presents a smartphone-integrated, fluorescence/colorimetric dual-mode sensing platform that combines fluorescence and colorimetric detection with support vector regression (SVR) for monitoring of acetamiprid in food. The system employs a sandwich-structured mechanism using MIPs/Fe3O4 as capture probes and aptamer-functionalized MIL-88B(Fe) as bifunctional signal probes. Uniquely, pyrophosphate (PPi) triggers the disassembly of MIL-88B(Fe), synchronously releasing fluorescent 2-aminoterephthalic acid ligands and Fe3+ ions, which subsequently catalyze Prussian blue formation for colorimetric readout. Furthermore, the integration of smartphone imaging and a SVR mode allows for intelligent translation of RGB color features into precise acetamiprid concentrations, facilitating rapid analysis. The biosensor demonstrates exceptional performance with detection limits of 41.0 pg mL-1 (fluorescence) and 45.0 pg mL-1 (colorimetric), maintaining high specificity in complex matrices. Successful application in fruit and vegetable extracts confirmed its practical utility, offering a sensitive, cross-validation, and field-deployable strategy for food safety monitoring.