Green synthesis of silver nanoparticle using rambutan (Nephelium lappaceum L.) peel extract and its antibacterial activity against Salmonella parathypi A.

Environmental Engineering Study Program, Universitas Islam Indonesia, Jln. Kaliurang KM 14.5, 55584 Yogyakarta, Indonesia

^* Corresponding author: puji.lestari@uii.ac.id

Abstract

Ag nanoparticles (AgNPs) have been synthesized via green method using rambutan (Nephelium lappaceum L.) peel (RP) extract. RP extract was prepared by washing the RP using tap water thoroughly and boiling it in distilled water at 70°C for 60 min. RP extract and AgNO₃ were used as the starting materials for the synthesis of AgNPs. RP extract was added to 10^-3 M AgNO₃ solution with a ratio by volume of 1:10 (RP : AgNO₃), stirred at room temperature. The solution’s color changes from reddish to dark brown, indicating the reduction of Ag⁺ in the solution. The synthesized AgNPs were characterized using UV-Visible Spectrophotometer, FTIR Spectrophotometer, and Scanning Electron Microscopy-Energy-dispersive X-ray Spectroscopy (SEM-EDS) instruments. UV-Visible spectra show that the AgNPs have the maximum absorption band at 450 nm which is typical for AgNPs. The FTIR spectra revealed that the protein in RP extract acts as the capping agent for the synthesized AgNPs. The synthesized AgNPs were tested for their antibacterial activity against Salmonella parathypi A. The antibacterial test shows that 50 μL of AgNPs resulted in the inhibition zone of 4 mm against the aforementioned microorganism.