Facile fabrication of multifunctional MOF-agarose aerogels for ultrasensitive dual-mode determination and efficient removal of glyphosate

In response to the urgent public demand for food safety and ecological protection, the sensitive detection and efficient removal of glyphosate (GPS) are of paramount importance. Herein, a multifunctional aerogel (Ru@ZrMOFs@AG) based on agarose (AG) and multi-emissive metal organic frameworks was rationally designed to simultaneously achieve colorimetric-fluorescence dual-mode detection and high-efficiency removal of GPS. The fabricated Ru@ZrMOFs@AG aerogel exhibited exceptional adsorption performance towards GPS pesticides, with a maximum adsorption capacity reaching 133.87 mg/g, and maintained good reusability following five consecutive adsorption/desorption cycles. Particularly, this composite material is endowed with dual-emission fluorescent characteristics (with emission peaks at 450 nm and 600 nm), while simultaneously exhibiting remarkable peroxidase-like activity. In the presence of hydrogen peroxide, it efficiently catalyzes the oxidation of colorless o-phenylenediamine into yellow 2,3-diaminophenazine. Notably, upon introduction of GPS into the system, the fluorescence intensity of Ru@ZrMOFs@AG at 450 nm significantly increased, whereas the emission at 600 nm remained stable; concurrently, GPS markedly inhibited its peroxidase-mimicking activity, leading to a decrease in the system’s absorbance. This dual-mode sensor enabled ultra-trace quantification of GPS, with detection limits of 0.98 ng/mL and 2.11 ng/mL for the ratiometric fluorescence and colorimetric modalities, respectively. Therefore, the developed Ru@ZrMOFs@AG aerogels combine stable fluorometric and colorimetric performance, exceptional adsorption capacity, and facile recyclability, offering an economically efficient and environmentally friendly solution for the simultaneous removal and monitoring of GPS.