Colorimetric Sensing of Mercury in Aqueous Solutions Using Silver Nanoparticles Prepared from <i>Synadenium glaucescens</i> Root Aqueous Extract

Abstract

Mercury contamination from various anthropogenic activities has been a recent global problem. Thus, developing cheap and efficient techniques for sensing mercury is significant for protecting humans and other organisms. The sensing of mercury using silver nanoparticles fabricated using phytochemicals extracted from Synadenium glaucescens roots (SYR) is reported. The successful synthesis of silver nanoparticles (SYR-AgNPs) was confirmed by a strong plasmon resonance in the UV-Vis spectrum at 420 nm due to oscillations of electrons in the silver nanoparticles. The potential use of fabricated silver nanoparticles for the sensing of mercury ions from aqueous solutions was investigated. The prepared silver nanoparticles displayed a high selectivity for detecting mercury against other divalent metal ions (Hg2+, Ba2+, Ca2+, Co2+, Cu2+, Fe2+, Mg2+, Ni2+, and Pb2+). The addition of mercury changed the SYR-AgNPs’ color to colorless, and the observed change in color was proportional to mercury concentration. The application of silver nanoparticles for the sensing of mercury displayed a detection limit of 11.3 µM. Therefore, the findings in the current study indicate that the prepared SYR-AgNPs can serve as a potentially sensitive and selective readily available method for sensing mercury ions in environmental samples. The method can be useful in advancing the application of green technology for sensing heavy metals from environmental samples.

Keywords

• silver nanoparticles
• <i>Synadenium glaucescens</i>
• Plasmon Surface Resonance
• mercury sensing