Quantum Dots-Engineered Flexible Hydrogel as Plant-Wearable Sensor for on-Site Profiling Dynamic Pesticide Degradation

Engineering wearable devices for in situ and on-site monitoring of pesticide residues from plants in a non-destructive manner is of great research value but remains a huge challenge. In this study, a plant-wearable fluorescence sensor CdTe CDs@PVA@AG, is designed and constructed by embedding CdTe QDs in polyvinyl alcohol (PVA) and agarose (AG)-co-assembled double-network hydrogel to transmit on-the-scene pesticides residues messages. Harnessing red emission and stimuli-responsive performance of CdTe QDs, as well as hydrogel's excellent flexibility, high adhesion, and porous network, CdTe CDs@PVA@AG is endowed with quantitative response to thiram at approximate to mu m level within 2 min through promoting fluorescence silence in conjunction with the transformation of images into primary colors as digital signals. More interestingly, CdTe CDs@PVA@AG is capable of being tightly pasted onto various crops' surfaces and then is not only explored to appraise pesticide residue levels but also to profile the dynamic pesticide degradation, in a non-destructive manner. This work opens up a new avenue to engineer plant-wearable devices for in situ, on-site, and non-destructive capturing of the pesticide residue information from crops, favoring the accurate monitoring of the health status of crops, and rapid and healthy development of smart agriculture.