Green synthesis and characterization of silver nanoparticles by Allium cepa L. to produce silver nano-coated fabric and their antimicrobial evaluation

This research work was proposed to study the antimicrobial activity of the silver nanocoated fabric with the purpose of producing good dressing and clothing material. We synthesized simple, ecofriendly, cost-effective and sustainable silver nanoparticles by using the aqueous extract of Allium cepa L. Here, A. cepaL. acts as a good reducing and capping agent that produced stable silver nanoparticles having particle size of range 36 +/- 1 to 98 +/- 2nm, Poly dispersiblity index 0.234 +/- 0.61 to 1.023 +/- 0.33 and Zeta potential -12 +/- 1.5mV to -26 +/- 1.2mV. The effect of temperature and extract volume used was considered for optimization of synthetic procedure. The nanocoated fabric was characterized for morphological study, size (using transmission electron microscopy (TEM) and field emission scanning electron microscopy (FE-SEM) and zeta-potential (Zeta Potentiometer). The presence of functional groups were observed by using attenuated total reflection-Fourier transform infrared (ATR-FTIR) and Raman spectroscopy. The crystallinity and structural property of the synthesized silver nanoparticles were studied in terms of Powder X-ray diffraction (PXRD). An IC50 value and zone of inhibition was studied which demonstrate that the silver nanocoated fabric have an excellent antibacterial property against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. Further nanocoated fabric material was washed (with function of time 0, 10, 25, and 50 laundry cycles) and still retained their anti-bacterial activity towards both strain. Initially there was 52g/ml of silver nanoparticles on the cotton fabric but after 50 laundry cycle in 500ml of distilled water the fabric showed 92% efficiency against gram positive and 90% efficacy toward gram negative bacteria. It was found that 4.16g/ml nano particles leached in case of S. Aureus and 5.2g/mL silver nanoparticles leached in case of E. coli. Nanocoated fabric material synthesized using green synthesis was found to be economical with good resistance to washing.