Design, synthesis, characterization, catalytic, fluorometric sensing, antimicrobial and antioxidant activities of Schiff base ligand capped AgNPs

Abstract

In recent days, the usage of biological and non-biological pollutants increases and it poses a significant threat to environmental and biological systems. Therefore, the present aim is to develop effective methods to treat such pollutants by using highly stable and small-sized Schiff base ligand capped silver nanoparticles (AgNPs) with a face-centered cubic (fcc) crystalline structure and the size range is 5–10 nm. The potent role of the resulting synthesized AgNPs was found as multiple platforms such as catalyst, sensor, antioxidant, and antimicrobial disinfectant. The synthesized AgNPs were characterized through UV–vis spectroscopy, PL, FTIR, XRD, SEM, and TEM. The FTIR spectrum of AgNPs exhibited the interacted functional groups of Schiff base and size was estimated by XRD and TEM. AgNPs were able to catalytically degrade approximately 95% of methylene blue (MB), rhodamine B (RhB), and eosin Y (EY) dyes within 80 min of reaction time using NaBH4. The fluorometric sensor studies of synthesized AgNPs showed selective sensing of the potentially hazardous Fe2+ ion in water. As an antimicrobial agent, the AgNPs are effective against both Gram-positive and Gram-negative bacteria; as well as fungi, with the zones of clearance as approximately compatible with standard drugs. The AgNPs displayed a greater ability to scavenge free radicals, especially DPPH when compared with AgNPs and ascorbic acid. Thus, the results of this study validate the triple role of AgNPs derived via a simple synthesis as a catalyst, sensor, antioxidant, and antimicrobial agent for effective environmental remediation.