Fabrication of Silver Nanoparticles in PVA Polymeric Films for Achieving Supreme Antimicrobial Nanocomposites: A Smarter Approach toward Food Packaging

Abstract

The extravagant use of traditional plastic packaging materials has increased the problem of food spoilage and toxicity in recent days. Nontoxic and environmentally benign alternatives to plastic materials for the packaging of foods are readily required. Silver nanoparticles (AgNPs) impregnated polyvinyl alcohol (PVA) thin films were fabricated after the synthesis of AgNPs using a simple chemical reduction method. The crystal structure, functional groups, microstructure, distribution, and absorbance pattern have been investigated using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), and UV–vis spectroscopy. The antibacterial activity of the PVA-AgNP nanocomposite was investigated by observing the width of the zone of inhibition, which is the area around the diffused sample on a culture plate with prevented bacterial growth. The MIC was determined using a dilution assay while maintaining a positive and negative control. The results of the experimental investigations confirmed the formation of AgNPs and the PVA-AgNP nanocomposite. The average length of the rod-shaped AgNPs was 5 μm with an average diameter of ∼90 nm. The nanocomposite showcased excellent antimicrobial activity against both Gram-positive Bacillus subtilis and Gram-negative Pseudomonas aeruginosa and Escherichia coli microorganisms, which was confirmed by the wide zone of inhibition with no bacterial growth. A dilution assay was set up to determine the MIC of AgNPs, which was found to be 20 μL/mL. In addition to the antimicrobial properties, the PVA-AgNP exhibited good water vapor retention ability for 5 days as well as preservation of ascorbic acid content of the nutritious foods after 14 days of packaging. Hence, the PVA-AgNP nanocomposite film fabricated in this work possesses supreme antimicrobial properties and acts as a potentially active food packaging material, substituting the toxic traditional plastic packaging materials.