A novel thiourea-based colorimetric chemosensor for sensitive and selective detection of sulphate ion in semi-aqueous medium

Abstract

Within the pool of naturally available anions, the sulphate anion has gained a certain level of notoriety by playing a critical role in contaminating the animal food chain, apart from disturbing marine life via paralysis of certain ecological cycles. Under such circumstances, it becomes imperative to regulate the influx of this potentially hazardous anion into the ecosystem. An important section of the remediation strategies in this area would involve an efficient sensing and quantification of this toxic anion, particularly in the natural water systems. In continuation of our efforts to exploit the unique photophysical properties of ligand-tagged nanoparticles to achieve selective ion-recognition potential, this report highlights the chemical synthesis and chemosensing efficacy of a new and selective sulphate-recognising organic receptor OR in aqueous medium. Upon decoration of OR onto ZnO nanoparticles, the nanohybrid OR@ZnO demonstrated a rapid response and selectivity towards the hydrogen sulphate anion, as marked by a significant alteration in the absorbance and fluorescence profile of OR@ZnO in aqueous system with a significantly low limit of detection (100 nM).