Sustainable Fabrication of an Eco-Friendly, Reusable Chitosan@Cotton@MOF Composite Sensor for 2,4-Dichlorophenoxyacetic Acid Herbicide and Nitroxoline Antibiotic
Subhrajyoti Ghosh, Debjit Mal, Srijan Mukherjee, Shyam Biswas
Abstract
The development of a reusable and eco-friendly sensor to monitor contamination in domestic water and food due to pharmaceutical wastes and herbicides is still beyond the grasp of modern-day researchers. To address such challenge, we designed a formamide functionalized Zr(IV)-organic framework ( 1 ). The porous framework ( S BET = 698 m 2 /g) was used for the selective and fast fluorescence sensing of an anti-microbial drug nitroxoline (NTX) and herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) in aqueous medium through turn-off and turn-on response, respectively. This is the first report of an optical sensor for both the analytes which can sense the targeted analytes within 5 s of its addition. The limits of detection (LOD) values are 50.8 and 10.9 nM for NTX and 2,4-D, respectively. Besides high reusability, the probe can sense targeted analytes in different environmental water samples, human body fluids (urine and serum for NTX), various fruits and vegetables (for 2,4-D) and wide range of pH media. For rapid and on-site naked eye detection, a cheap, handy, reusable, and biocompatible chitosan@cotton@MOF composite was fabricated. The composite was capable to change its color up to nanomolar-level concentrations. The possible mechanisms of both sensing events were investigated with the help of appropriate instrumental supports.