Picomolar level nonchemodosimetric probing of bisulfate in pure aqueous buffer at neutral pH by mechanosynthesized zwitterions and their unprecedented application in the estimation of bisulfate in edible plant foods, drugs, and urine samples.

Environmental remediation with a single platform for selective sensing and removal of toxic analytes with recyclability of the material has always been a desirable system for sustainability. However, materials comprising all the abovementioned advantages are rarely known for oxoanions. We herein developed a fluorogenic napthalimide-based functionalized mesoporous silica material (SiO2@NBDBIA) as a signaling and remediation system for oxoanions (CrO4 2–, Cr2O7 2–, and MnO4 –) from a pool of several anions. The fluorescence quenching of the SiO2@NBDBIA material in the presence of CrO4 2–, Cr2O7 2–, and MnO4 – ions gives the limit of detection (LOD) values of 6.23, 25.2, and 20.32 ppb, respectively, which are well below the maximum contaminant level demarcated by the United States Environmental Protection Agency. The maximum adsorption capacities of the material for the abovementioned oxoanions are found to be 352, 363, and 330 mg/g, respectively, which are well above those mentioned in the literature reports. Contrary to the literature-dominated irreversible ion-exchange mechanism, the reversible hydrogen-bonded binding of the material with the oxoanions leads to the recyclability of the material easily, which is very rare in the literature. The DFT calculations were performed to examine the interactions between the material and oxoanions. For real applications, this material was also used as a fluorescence probe to detect these oxoanions in the actual water samples, and more interestingly, used as a biosensing probe for these oxoanions in the living organism Artemia salina through fluorescence imaging. Thus, the SiO2@NBDBIA material is a unique example of recyclable material for detecting and remediating oxoanions.