Environment-friendly method of silver nanoparticle synthesis from used green tea bag extracts and a silver nanoparticle-specific colorimetric detection probe for cadmium ions in different water samples

Abstract

Single-use green tea bags are disposed of after one use, and an eco-friendly approach for synthesizing silver nanoparticles (Ag-NPs) utilising these bags was developed to investigate the viability of an alternative reducing agent precursor for nanoparticle synthesis, which is both sustainable and biocompatible and derived from silver nitrate salt. The green-produced UGTB-AgNPs were studied and validated using ultraviolet-visible (UV-vis) spectroscopy, which exhibited a surface plasmon resonance (SPR) peak at 421 nm. UGTB-AgNPs nanoparticles were studied using Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The UGBT-stabilized AgNPs facilitated the detection of Cd²⁺ ions by the SPR phenomenon and the aggregation state of nanoparticles within the concentration range of 5 μM to 50 μM via visual observation. These are optical sensors capable of delivering real-time surveillance of molecule binding occurrences. They exhibit heightened sensitivity for the detection of cadmium ions, particularly when integrated with nanoparticles to enhance sensor surface characteristics, becoming invaluable in forensic chemistry.