TPB-DMTP@S-CDs/MnO2 Fluorescence Composite on a Dual-Emission-Capture Sensor Module for Fingerprint Recognition of Organophosphorus Pesticides

Residues of organophosphorus pesticides (OPs) raise considerable concern, while identifying OPs from unknown sources is still a challenge to onsite fluorescence techniques. Herein, a dual-emission-capture sensor module, based on a TPB-DMTP@S-CDs/MnO2 fluorescence composite, is developed for OP fingerprint recognition. TPB- DMTP@ S-CDs/ MnO2, synthesized by a hydrothermal method and self-assembly, is spectrographically validated as a dual-wavelength fluorescence source. OP-sensitive catalysis (acetylcholinesterase on acetylthiocholine chloride) is designed to regulate fluorescence by decomposing quenchable MnO2. A flexibly fabricated sensor module supports the optimal dual-wavelength fluorescence excitations and captures and converts fluorescence emissions into equivalent photocurrents for feasible access. The most prominent finding is that dual-fluorescence emissions alternatively respond to levels, species, and multi-pH pretreatments of OPs due to varied MnO2 sizes and distributions. Therefore, OP fingerprint recognition is conducted by refining the multidimensional information from fluorescence-triggered photocurrents and preset hydrolyzation using principal component analysis and the rule of maximum covariance. The recommended method provides a wide dynamic range (1 x 10(-6) x 12 mu g mL(-1)), a good limit of detection (7.9 x 10(-7) mu g mL(-1)), 15-day stability, and good selectivity to guarantee fingerprint recognition. For laboratory and natural samples, this method credibly identifies a single kind of OPs from multiple species at trace levels (10(-5) mu g mL(-1)) and performs well in two-component and multicomponent analyses.

Automated summary

A dual-emission-capture sensor module is developed for OP fingerprint recognition using a TPB-DMTP@S-CDs/MnO2 fluorescence composite. By regulating fluorescence intensity and utilizing principal component analysis and the rule of maximum covariance, organic phosphorus pesticides can be accurately identified under different spectral and pH conditions.