Green synthesis of antipathogenic particles by utilizing the citrus plant waste and their application in medicated fabrics

Antipathogenic fabrics coated with different types of metallic nanoparticles were developed for the use in healthcare sector. The citrus plant waste was collected and processed to extract the bioactive molecules for the green synthesis of metal particles. Here, the citrus extract was used for a dual purpose, as a bio reductant and also as a bio dispersant (D-limonene). Subsequently, the green synthesis of a highly concentrated and stable colloidal dispersion of Silver nanoparticles (Ag-NPs), Copper nanoparticles (Cu-NPs) and Zinc Oxide (ZnO-NPs) was carried out using the self-assembled respective salts and green extracted reducing agents without using any other hazardous chemicals. Furthermore, the effect of the loaded D-limonene as a dispersant was justified by PDI, Zeta potential, particle size analysis and Dynamic Light Scattering (DLS). The synthesized particles were assessed for their morphology and geometric characteristics by Scanning Electron Microscopy (SEM), revealing the formation of particles with spherical and oval shapes. The justification for the formation of particles was also analyzed by using Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) techniques. In the next step, the synthesized Ag-NPs, Cu-NPs and ZnO-NPs were applied to cotton fabric and their antipathogenic properties (antibacterial, antiviral, and antifungal) before and after severe washing were characterized. It was observed that the nanoparticles applied fabric at higher concentration (5g) exhibit even covering of fiber surface, average particles sizes between 350 and 470 nm, with excellent antimicrobial activity against Escherichia coli (3.4 ± 0.35 mm) and Staphylococcus aureus (5.5 ± 0.19 mm). The untreated fabric had a log CFU/ml value of 5.43, indicating no antibacterial effectiveness of the control sample. However, the log values of all the treated samples were significantly lower. Moreover, the intensity of concentration of zinc silver and copper particles explains the 88.48 %, 85.01 % and 94.23% antifungal activity respectively. While antiviral activity (84% reduction) was also highest against copper nanoparticles coated fabric. The level of significance against antipathogenic activities among all particles coated samples was analysed by applying the statistical analysis of simple linear regression with paired t test. In addition the comfort parameters (air and water vapor permeability) for developed medicated textiles were also analyzed.