Unmodified Green Silver Nanoparticles as Multisensor for Zn2+ and Catalyst for Environmental Remediation.

This paper details the selective optical, fluorescent and electrochemical detection of Zn²⁺ among various divalent metal ions in aqueous solution by the green synthesized silver nanoparticles (AgNP) using the fresh extract of Myristica fragrans (MF) with the aid of microwave energy. The synthesized silver nanoparticles stabilized with MF were analysed using UV-vis., Fourier-transform infrared (FT-IR), X-ray diffraction (XRD), and transmission electron microscopy (TEM) techniques. Due to the effective complexation between silver nanoparticles and metal ions, absorbance of AgNP-MF diminished with increasing concentration of Zn²⁺. This is visually identified through the color changes. Fluorescent sensing studies involved the changes in fluorescent intensity of AgNP-MF in the presence of Zn²⁺. Electrochemical sensing of Zn²⁺ was carried through cyclic and differential pulse voltammetric techniques using AgNP-MF modified platinum electrode (AgNP-MF􀀀 Pt). The developed electrochemical sensor showed a limit of detection (LOD) of 0.6148 μM and its good sensing ability was checked for the detection of Zn²⁺ in environmental water samples. Recoveries of Zn²⁺ in the various real water samples were obtained in the range from 100.2% to 100.6%. The multifunctional utility of the AgNP-MF as a catalyst towards the reduction of two environmentally toxic contaminants such as o/p-nitroanilines through NaBH₄ was also evaluated. The complete degradations were achieved within few minutes and the reactions followed pseudo first order kinetics. The effect of catalytic dosage on the rate of reduction reactions was also studied. [ABSTRACT FROM AUTHOR]