Sunlight-assisted greenly synthesised silver nanoparticles for highly selective mercury ion sensing, biomedical and photocatalytic applications
Abu Bakar Siddique, Muhammad Ashraf Shaheen, Azhar Abbas, Yasir Zaman, Hatem M.A. Amin, Mohammad Mahtab Alam, Nada K. Alharbi, Fatma Alshehri, Ashwag Shami, Fakhria A. Al‐Joufi, Akbar Ali
Abstract
Water pollution by heavy metal ions, azo dyes, and bacteria is an emerging problem that needs to be addressed via a sustainable, facile treatment approach. Herein, Phytochemical-enriched Carissa macrocarpa fruit extract was used as a reducing and stabilising agent in this one-pot, economical, and environmentally safe method of biosynthesizing AgNPs under direct sunlight. CMFE@AgNPs were completely characterised by employing UV-Vis, FTIR, HR-TEM, EDX, XRD, DLS, and ZP analysis. The AgNPs are spherical with 50 nm particle size, highly stable, and with a face-centred cubic structure. Based on AgNPs’ colour quenching, the CMFE@AgNPs demonstrated highly selective colorimetric sensing of Hg2+ in spiked distilled, tap, and river water samples with a remarkable detection limit of 18.45 μM. Additionally, CMFE@AgNPs revealed efficient photocatalytic degradation of methyl orange (77.3%) and methylene blue (88.9%) in just 150 minutes of exposure to sunlight. Thermodynamic and kinetic insight to the degradation reaction was investigated. Effective antibacterial action against both gram-positive and gram-negative bacteria has also been demonstrated by CMFE@AgNPs. With an IC50 value of 23.4 ± 1.5 μg/mL, CMFE@AgNPs have demonstrated strong antioxidant activity in comparison to normal gallic acid (IC50 = 22.3 ± 1.2 μg/mL). Hence, this facile approach for CMFE-assisted production of AgNPs may have a promising potential in wastewater remediation and antioxidant ointments.