Synthesis of nanosilver paper using rambutan (Nephelium lappaceum l.) fruit peel extract under sunlight irradiation as a mercury ion detector

In Indonesia, mercury contamination poses a serious threat to aquatic ecosystems and human health. Although conventional detection methods are highly accurate, their application is limited by sophisticated instrumentation and complex sample preparation. This study reports the eco-friendly and cost-effective biosynthesis of silver nanoparticle (AgNP)-based paper using rambutan (Nephelium lappaceum L.) fruit peel aqueous extract (RFPAE) under sunlight exposure for the rapid detection of mercury ions (Hg۲+). RFPAE contains active compounds (such as isofraxidin) with ultra-strong antioxidant activity (IC۵۰ = ۱۱.۷۳ ppm), serving as a bioreductant in the fabrication of the nanosilver paper. The nanosilver paper was successfully synthesized, exhibiting a spherical morphology with particle sizes ranging from ۴۵.۸۲ to ۷۲.۶۰ nm. Simple linear regression analysis revealed a significant inverse relationship between RFPAE concentration and the size of the synthesized AgNPs. As a colorimetric sensor, the nanosilver paper is capable of detecting mercury ions with a Limit of Detection (LOD) of ۵.۴۰۸ ppb and a Limit of Quantitation (LOQ) of ۱۶.۳۸۸ ppb. A ۱۲-day stability test confirmed that the nanosilver paper remained sensitive in detecting Hg۲+. Furthermore, the sensor demonstrated high selectivity toward Hg۲+ compared to other metal ions. These results highlight the great potential of this nanosilver paper as a practical, portable preliminary screening tool for on-site environmental monitoring.

کلیدواژه ها:

Synthesis ، nanosilver paper ، mercury detctor ، selective ، simple ، portable