Dual-mode fluorescence/colorimetric aptasensor based on Zn,Ce-MOF nanocomposite for sensitive detection of isocarbophos

Background A dual-mode fluorescence/colorimetric aptasensor was developed for the sensitive detection of isocarbophos, an organophosphorus pesticide posing significant public health risks. Using Zn,Ce-MOF nanocomposites, this sensor integrated magnetic separation and signal amplification. This integrated biosensing strategy offers a promising tool for environmental safety assurance and food quality control applications. Results The Zn,Ce-MOF nanozyme of this sensor serves as both a carrier of 3,3′,5,5′-tetramethylbenzidine (TMB) and oxidase mimic, facilitating enzyme-free TMB oxidation. The dual-readout system enables self-validating detection through independent channels (fluorescence LOD: 0.06 ng mL −1 ; colorimetric LOD: 0.09 ng mL −1 ), with robust performance, high interferent selectivity, and reproducibility. Practical validation in spiked agricultural samples yielded recovery rates of 97.7–113.6 %, confirming the platform's suitability for field-deployable pesticide monitoring. Significance This work developed a fluorescence/visual aptasensor with self-assembled TMB/Au/Zn,Ce-MOF probes for one-step magnetic separation dual-mode detection. This integrated biosensing strategy improves detection efficiency and accuracy, offering a general strategy for multimodal biosensors.