Eco-friendly biosynthesis and characterization of silver nanoparticles from Solanum lycopersicum (Tomato) peel waste and its application in disinfecting metallic surfaces

Abstract According to their special physio-chemical properties, Nanoparticles have gained worldwide attention as a new bio-alternative for chemical control agents. This investigation aims to the eco-friendly synthesis of nanosilver particles from tomato peel extract (TPE-AgNPs) and evaluates their characteristics and inhibitory activities against pathogenic bacteria and fungi as well as their role in metallic surface disinfecting. To initiate biosynthesis, tomato peel extract was mixed with silver nitrate (AgNO 3 ) solution until the color changes to reddish brown. Ultraviolet (UV-Visible) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) analysis, and transmission electron microscopy (TEM) techniques were used to characterize biosynthesized TPE-AgNPs. Results recorded that obtained TPE-AgNPs had a strong score (238nm) of Plasmon resonance (SPR) by SPR of 4.5. Functional groups of carboxyl, hydroxyl, and phenolic groups existed and were detected by the FTIR spectrum. The synthesized TPE-AgNPs had an amorphous nature which was confirmed by XRD analysis. TEM analysis showed spherical TPE-AgNPs sized from 4.44-27.59nm. The biosynthesized TPE-AgNPs had a negative zeta potential of -68.44 mV. The inhibitory activities of synthesized TPE-AgNPs were evaluated against eleven microbial pathogenic using well diffusion method, inhibition zone diameter (IZD) was measured in centimeters. Results showed that B. subtilis and E.coli was the most sensitive pathogens with IZD of 4.0 and 0.92cm, respectively However, L. monocytogenes and S. sonnei were the most resistant pathogens with IZD of 0.92 and 0.90 cm, respectively. Synthesized TPE-AgNPs from tomato peels had good inhibitory potentials against pathogenic fungi with IZD of 3.0 and 0.92cm against A. solani and C. albicans , respectively. Applying the use of TPE-AgNPs as bio disinfectant significantly decreased the microbial load of metallic blades and proves its efficiency as a disinfectant agent after 120min. of contacting. So, more applications on disinfecting metallic surfaces such as dentistry are indeed needed.