Portable Self-Powered/Colorimetric Dual-Mode Sensing Platform Based on Multifunctional Bioconjugates for Precise...

Neonicotinoid insecticides have been widely applied in modern agriculture to improve crop productivity, but their residues have adverse impacts on the environment and human health. Hence, to address these issues, a portable self-powered/colorimetric dual-mode sensing platform was developed for the simple, rapid, precise, and sensitive on-site detection of acetamiprid (ATM) residues in vegetables. In this case, a multifunctional bioconjugate with specific recognition capability, excellent enzyme-like activity, and loading capacity is the key to the sensing design. Using an Eppendorf (EP) tube as a miniaturized laboratory, the bioconjugates and the colorimetric test strip were integrated into the EP tube, and combined with a nanozyme-based self-powered sensing platform (with an area of 1.5 × 1.5 cm²), accurate on-site detection of ATM was achieved, with detection limits as low as 2.9 fg·mL^-1 (self-powered method) and 31.5 fg·mL^-1 (colorimetry), respectively. Notably, we simulated the actual insecticidal situation based on the field application concentration and quantified the pesticide residues in vegetables. The relative errors of our method and the standard high-performance liquid chromatography method were 0.15% (the self-powered method) and 1.8% (colorimetry), respectively. The portable dual-mode sensing platform with high sensitivity and accuracy opened up a new avenue for the development of on-site pesticide residue analysis in the next generation of agricultural products.