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

Dual-mode sensor integrates fluorescence/colorimetric detection for cross-validated acetamiprid monitoring. • Synergistic recognition by MIP and aptamer enhances specificity in complex food matrices. • The MIL-88B (Fe) was used as a dual-signal probe triggered by PPi. • The integration of smartphone-based colorimetric readout and machine learning enhances field applicability. • Achieves ultra-sensitive detection with high recovery in real samples. 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/Fe 3 O 4 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 Fe 3+ 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. Download: Download high-res image (176KB) Download: Download full-size image