Cellulose Nanofiber-Templated Metal-Organic Frameworks for Fluorescent Detection of Methyl Parathion Pesticides

Methyl parathion is a typical organophosphorus pesticide that poses threats to the global environment and human health. In this study, we developed a portable 2D sensing pad for monitoring methyl parathion based on aggregation-induced emission (AIE) properties of innovated hybrid material that integrates cellulose nanofibers (CNFs) with luminescent metal-organic frameworks (LMOFs). The hybrid material enhanced the flexibility and moldability of the LMOFs and significantly improved scalability of the sensing material. The resulting CNF/LMOF material was shaped into a 2D pad, exhibiting fluorescent properties under UV exposure. The fluorescence of the hybrid pad was quenchable upon exposure to methyl parathion. This host-guest interaction enabled the precise quantification of the pesticide's concentration by monitoring the intensity variation of the fluorescence at 405 nm wavelength. We further engineered these hybrid pad prototypes into a user-friendly and portable sensing kit, and then validated them with real sample testing. Time-dependent Density Functional Theory (TD-DFT) calculations were employed to elucidate the underlying fluorescence quenching mechanism triggered by methyl parathion. This work introduces a practical and sustainable sensing platform for pesticide detection.