Design of a Highly Selective Benzimidazole-Based Derivative for Optical and Solid-State Detection of Zinc Ion.

A novel series of benzimidazole-based molecules mimicking biological receptors, which exhibit selective coordination with zinc ions, were designed and synthesized. The photochromic behavior of these derivatives with various metal ions suggests a selective interaction of one of the receptors 2-(pyridin-2-yl)-4,7-di(thiophen-2-yl)-3H-benzo[d]imidazole (2c) with zinc ion. The lower limit of detection by photoluminescence quenching was determined to be 16 nM. The mechanism of selective complexation was elucidated by 1H nuclear magnetic resonance titrations and dynamic light scattering analysis. The stoichiometry of the formation of the Zn(2c)2 complex was evaluated by single-crystal X-ray diffraction and mass spectral techniques and calculated to be 2:1 (L:M). A change in the electronic energy levels on the sensor analyte interaction was observed by both ultraviolet photoelectron spectroscopy analysis and by density functional theory calculations, suggesting an electroactive semiconductor behavior. A symmetric Schottky structured sensor device was fabricated using the receptor 2c as the active sensing layer. A distinct change in current-voltage characteristics between the receptor and the complex suggests that the fabricated device could be used as a solid-state sensor for detecting zinc ion.

Adsorption and detoxification of pharmaceutical compounds from wastewater using nanomaterials: A review on mechanism, kinetics, valorization and circular economy.

Antibiotics overuse, inappropriate conduct, and discharge have led to adverse effects on various ecosystems. The occurrence of antibiotics in surface and drinking water is a matter of global concern. It is responsible for multiple disorders, including disruption of endocrine hormones and high chronic toxicity. The hospitals, pharmaceutical industries, households, cattle farms, and aquaculture are the primary discharging sources of antibiotics into the environment. This review provides complete detail on applying different nanomaterials or nanoparticles for the efficient removal of antibiotics from the diverse ecosystem with a broader perspective. Efforts have been made to focus on the degradation pathways and mechanism of antibiotic degradation using nanomaterials. More light has been shed on applying nanostructures in photocatalysis, which would be an economical and efficient solution. The nanoscale material or nanoparticles have incredible potential for mineralizing pharmaceutical compounds in aqueous solutions at low cost, easy handling characteristics, and high efficacy. Furthermore, nanoparticles can absorb the pharmaceutical by-products and wastes at a minimum cost as they can be easily recycled. With the increasing number of research in this direction, the valorization of pharmaceutical wastes and by-products will continue to expand as we progress from old conventional approaches towards nanotechnology. The utilization of nanomaterials in pharmaceutical wastewater remediation is discussed with a major focus on valorization, energy generation, and minimization and its role in the circular economy creating sustainable development.