Morphological characterization and synthesis of metallic oxide nanoparticles of selected Bluegreen algae of District Mianwali

Abstract

In this study microalgae of District Minawali has been explored for diversity and as potential source for nano particles and their application. A total of 73 species belonging to different 34 genera of algae were collected from different sites of District Mianwali during summer and winter season to investigate the effect of the physio-chemical parameters on the diversity of microalgae. The dominant division was Chlorophyta, having 33 species from different genera such as Spirogyra, Cosmarium, Closterium, Cladophora, Microspore, Mougeotia, etc, followed by Cyanophyta (20 species) and Bacillariophyta (20 species). The species of genus Achanthidium, Diprora, Cymbella, Cosmarium, Cladophora, Navicula were identified for the first time from Pakistan. Physio-chemical parameters of the water affect the diversity of microalgae. The most significant parameters are nitrate, phosphate, pH, and dissolved oxygen. In present study, Iron oxide IONPs and Ag-NPs were synthesized using Oscillatoria limnetica and Anabaena azollae as a strong reducing, stabilizing and capping agents. Further, the synthesized nanopartic1es were characterized through different methods like UV -visible spectroscopy, Fourier transform infrared (FTIR), X-ray diffractive analysis (XRD), scanning electron microscope (SEM), and Energy dispersive X-ray spectroscopy (EDX). IONPs and Ag NPs were confirmed by using UV-visible spectroscopy peak at 47lnm and 467nm. SEM analysis shows hematite trigonal rhombohedral and FCC-cubic morphology and average grain siz.e 23.33nm of Ag-NPs and 38nm of IONPs were obtained. Furthermore, different in vitro biological assays were perfOimed and showed imp0l1ant therapeutic potentials. Antimicrobial assay of bio-synthesized NPs was performed against different Gram positive and Gram negative bacterial strains. E coli was found to be least susceptible strain (MIC:35/lg/mL, 27/lg/mL) and B. subtilis was found to be most susceptible strain with (MIC: 14/lg/mL, 10/lg/mL). The maximum antifungal assay was also observed for Aspergillus versicolor (MIC:27/lg/mL, 32/lg/mL). The cytotoxic assay ofNPs was also studied using brine shrimp cytotoxicity assay and their LDso value was reported as 47 for Ag-NPs and 49/lg/ml, for IONPs. For toxicological evaluation, NPs was susceptible in relation to human RBC (ICso: > 200 /lg/mL), considering NPs safe for nanomedicine. The antioxidant assay, (DPPH) 2,2-diphenyl I-picrylhydrazyly (73% and 76%) was detemlined for NPs. Oscillatoria limnetica and Anabaena azollae synthesized IONPs, and Ag-NPs showed great biological potentials and can be used for further differ~nt in vitro and in vivo therapeutic purposes