Optical and phytochemical detection of decayed food items using yeast mediated silver nanoparticle

This study emphasized the use of silver nanoparticle (AgNPs) produced from yeast isolate to detect decayed food items like tomatoes, doughnut, and bread. The synthesized AgNPs was monitored via its surface plasmon resonance (SPR) reading with UV-Visible spectrophotometer and later characterized with Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometer (XRD), scanning electron microscope (SEM), and energy dispersed x-ray (EDX). The UV-Visible reading were observed between wavelength of 350 - 450 nm, while XRD diffraction showed three distinct peaks at 38.08°, 44.28° and 64.51° corresponding to the plane of (111), (200) and (220) suggesting the production of AgNPs. The optical potency of the synthesized AgNPs using decayed tomatoes was observed via color change from the initial light orange color of AgNPs to deep brown color after detection of volatile metabolites from decayed food items and this was confirmed with a red shift noticed on the 6th day when the AgNPs wavelength changed from initial range of 350 - 450 nm to 520 nm when monitored with UV-Visible spectrophotometer. The study demonstrates that silver nanoparticles synthesized from yeast isolates can serve as effective nanosensors for detecting volatile metabolites emitted by decaying food items such as tomatoes, doughnuts, and bread. KEY WORDS: AgNPs, Optical sensor, Food spoilage, Nanoparticles Bull. Chem. Soc. Ethiop. 2025, 39(5), 921-936. DOI: https://dx.doi.org/10.4314/bcse.v39i5.9