Silver nanoparticles synthesized from Bacillus subtilis for detection of deterioration in the post-harvest spoilage of fruit

Abstract Global food shortage is mainly due to the post-harvest spoilage of food, rather than its under-production, especially in the sub-Saharan African countries. Rapid detection tools for the spoilage of fruit such as banana ( Musa acuminata) would be a great resource in alleviating losses during post-harvest storage. In this study, silver-based colloidal nanoparticle (AgNPs) solution was synthesized using culture supernatant or wet biomass (cell pellets) of Bacillus subtilis . The synthesized silver nanoparticles solution was confirmed using UV–Vis Spectrophotometer and further characterized using Scanning Electron Microscope (SEM), X-ray Diffractometer (XRD) and Fourier Transmission Infrared (FT-IR), and then evaluated as a colorimetric sensor for the volatile compound released during the deterioration of Musa acuminata . The original reddish brown colour of the silver nanoparticle solution changed to light brown by the end of the fourth day and finally turned transparent on the tenth day. Simultaneous analysis carried out by UV–Vis spectroscopy corroborates our investigation of AgNPs as a colorimetric sensor displaying selectivity and specificity for 1,2-Benzenedicarboxylic acid, bis (2-methyl propyl) ester which was released during the deterioration of Musa acuminata . The use of colorimetric sensor as conducted in this study will help in easy detection for control of crop deterioration.