Target-Responsive Metal–Organic Framework Nanosystem with Synergetic Sensitive Detection and Controllable Degradation against the Pesticide Triazophos in Contaminated Samples for Environment Assessment and Food Safety

Abstract

Developing sensitive practical sensors for monitoring pesticide residues in edible foods and environmental samples is vital for food safety and environmental protection. Enzyme-inhibited biosensors offer effective alternative sensing strategies by using the inherent characteristics of pesticides. To further improve the degradation function of pesticide sensors, here, a target-triggered porphyrin metal–organic framework (MOF)-based nanosystem was designed with the synergetic bifunction of sensitive detection and controllable degradation of the triazophos pesticide. As a result of triazophos-inhibited glutathione consumption, the MOF collapsed and released the ligand porphyrin, leading to the recovery of fluorescence and photosensitization of the free porphyrin. The fluorescence recovery resulted in a sensitive detection limit of 0.6 ng mL–1 for triazophos, which was also applied for the determination of contaminated samples and bioaccumulation in rice. Furthermore, the target-activated photocatalytic ability of porphyrin endowed the system with the ability to effectively generate reactive oxygen species for degrading triazophos with a removal rate of ∼85%, achieving eco-friendly synergetic detection and photodegradation in a controllable way. Therefore, the intelligent multifunctional MOF system demonstrated the potential of programmable systems for jointly controllable tracking and elimination of pesticide residues in the environment and opened a new avenue for designing a precise mechanism for stimulus-triggered degradation of pesticide residues accompanied by sensitive detection for environmental friendliness and food safety.

Bimetallic Porphyrin-Based Metal–Organic Framework as a Superior Photocatalyst for Enhanced Photocatalytic Hydrogen Production

“…Porphyrins are tetraphenyl compounds with a structure highly similar to chlorophyll in plants and heme in animals, containing four pyrrole rings and the methylene group attached in the middle of the adjacent pyrrole ring. , The basic porphyrins are called porphins, in which all porphyrin derivatives have corresponding substituents at the meso-position or β-position. , Common substituents include functional groups such as amino, hydroxyl, and carboxyl, which are usually required and extremely important active sites for the formation of porphyrin-based MOFs. , In addition, the N–H group in the highly aromatic macrocycles of porphyrins is easily metallized, which also provides a good reactive site. , Therefore, in recent years, various types of porphyrin-based MOFs have been designed, synthesized, and widely applied in a variety of fields, embracing chemical detection, pharmaceutical therapy, , hydrogen production from decomposing water, carbon dioxide fixation, and selective transformation of organic compounds . Due to the abundant pore channels, good light absorption ability, and adjustable crystal structure, porphyrin-based MOFs displayed extraordinary properties in the field of photocatalysis. − However, the photocatalytic performance of monometallic modified porphyrin-based MOF is usually affected by the high recombination rate of photoinduced electron hole pairs.…”