Sulfonamide-functionalized silver nanoparticles as an analytical nanoprobe for selective Ni(II) sensing with synergistic antimicrobial activity

Abstract

Developing stabilized silver nanoparticles (Ag NPs) is key in promoting their sensing and antimicrobial performance. The present work reports a facile novel synthesis of Ag NPs functionalized with 4-(phenylsulphonamido)benzoic acid (PSBA) and mediated by sunlight irradiation. Here PSBA is used as a reductant and a stabilizer in the synthesis of Ag NPs and provides binding sites to Ni2+. The synthesized NPs were investigated as an analytical probe for the selective colorimetric sensing of Ni2+ and antimicrobial agent. The synthesis, stabilization of Ag NPs and their detection mechanism were characterized using UV–vis, FTIR, XRD, DLS, Zeta-potential (ZP), and cyclic voltammetry. The particles revealed a hydrodynamic size of 45 nm and the characteristic surface plasmon resonance (SPR) peak for Ag NPs is centred at 410 nm in the UV–vis spectrum. The particles revealed excellent colloidal stability, as evidenced by the ZP value (–30 mV). These Ag NPs@PSBA selectively interacted with Ni2+ among other metal ions in an aqueous solution, as illustrated by a significant change in color and SPR peak due to an aggregation effect. The Ag NPs assay exhibited a lower limit of detection (LOD) of 48 nM for Ni2+ detection and was successfully tested in real water samples. Additionally, Ag NPs@PSBA revealed significantly improved antimicrobial activity against various food-borne pathogenic bacteria due to a synergistic antimicrobial effect. Hence, our approach opens a new avenue to design novel and effective functionalized nanomaterials for real-world sensing and biomedical applications.