Porphyrin-modified hydrogel loading Active Deep Eutectic Solvents (ADESs) for photothermal-prompted release applied in green pesticide delivery

The excessive use of pesticides and their low utilization efficiency pose significant environmental and agricultural challenges. Developing green and efficient pesticide delivery systems for vegetables is of great importance. In this study, flonicamid-based ADESs were successfully prepared, among which flonicamid-citric acid monohydrate (1:6) exhibited enhanced insecticidal activity against Plutella xylostella compared with the commercial formulation, along with improved biocompatibility. Furthermore, a porphyrin derivative (TAPP-EO) with enhanced photothermal performance was synthesized and copolymerized with N-isopropylacrylamide (NIPAM) to construct a photothermal-responsive hydrogel. The hydrogel enabled efficient and triggered release of ADES, achieving a cumulative release of 96.32% within 24 h under infrared irradiation, following a Fickian diffusion mechanism. Additionally, the system demonstrated good stability, strong adhesion properties, and no adverse effects on plant growth even at high concentrations. The integration of ADESs with a photothermal-responsive hydrogel system offers an efficient, controlled, and environmentally friendly strategy for crops.