Adsorption, antimicrobial and wound healing activities of biosynthesised zinc oxide nanoparticles

Using plant extracts has been interesting as possible eco-friendly methods to synthesis and stabilize different types of nanoparticles. Zinc oxide nanoparticles (ZnO-NPs) can be used as effective adsorbent due to their high surface area to volume ratio and high spontaneous adsorption properties. In this research, ZnO-NPs were synthesized and stabilized to use as an effective adsorbent material for removing two carcinogenic azo dyes: Malachite green and Congo red. It is also used as an antibacterial active material to enhance mouse skin wound healing. The fabrication and stabilization of ZnO-NPs were performed usingAloe barbadensisleaf extract. The morphology and structure of the as-synthesized ZnO-NPs were investigated by X-ray diffraction, scanning electron microscopy, Fourier transforms infrared spectroscopy and UV-Vis spectroscopy. The fabricated ZnO-NPs were applied as an adsorbent for the removal of Malachite green, a cationic azo dye, and Congo red, an anionic azo dye. The ZnO-NPs achieved adsorption efficiency of 90.7% for Malachite green azo dye within 90 min at the maximum amount of 70 mg/ml. Congo red dye was adsorbed at the efficiency of 92.30% within 120 min at 80 mg/ml maximum concentration of ZnO-NPs. Using the batch process, different parameters (time, pH, amount of adsorbent) during the adsorption process were elucidated. The results confined the applicability of ZnO-NPs as an efficient adsorbent for Malachite green and Congo red dyes. Also, the synthesised ZnO-NPs demonstrated a powerful antimicrobial activity against four types of bacterial strains ofBacillus subtilis,Klebsiella pneumonia,Bacillus licheniformisandEscherichia coli, and two types of fungi strains ofAspergillus nigerandCandida albicans. The healing efficiency of mouse wound was studied using ZnO-NP/silica gel (ZnO-NP/SG) dressings due to its extensive evidence on healing property. The microscopic investigations of the wound area are reduced significantly using ZnO-NP/SG-30 ppm dressings within 11 days of observation as compared to ZnO-NPs of the control sample. These findings elaborated that as-synthesized dressing enhanced the skin repairing on the wound surface and support its usage in the future.