Application of green silver nano-particles as anti-bacterial and photo-catalytic degradation of azo dye in wastewater
Zainab Haider Ali, Lubna Abdulazeem, Wafaa A. Kadhim, Mazin Hadi Kzar, Osamah J. Al-sareji
Abstract
Ensuring everyone enjoys healthy lifestyles and well-being at all ages, Progress has been made in increasing access to clean water and sanitation facilities and reducing the spread of epidemics and diseases. The synthesis of nano-particles (NPs) by using microalgae is a new nanobiotechnology due to the use of the biomolecular (corona) of microalgae as a capping and reducing agent for NP creation. This investigation explores the capacity of a distinct indigenous microalgal strain to synthesize silver nano-particles (AgNPs), as well as its effectiveness against multi-drug resistant (MDR) bacteria and its ability to degrade Azo dye (Methyl Red) in wastewater. An extract of Spirulina platensis was obtained from a local source to synthesize silver nano-particles (AgNPs). The synthesized AgNPs were subsequently subjected to characterization utilizing several analytical methods, namely UV-visible spectroscopy, scanning electron microscopy (SEM), X-ray diffraction, and Fourier transform infrared spectroscopy (FTIR analysis). Subsequently, the disc diffusion method assessed their anti-bacterial efficacy against multi-drug resistant (MDR) bacteria and their ability to degrade Azo dye (Methyl Red) in wastewater. The nano-particles produced through biological synthesis exhibited a prominent peak in the UV-visible spectrum at a wavelength of 430 nm. Furthermore, these nano-particles were determined to possess a crystalline nature, with an average size of 28.72 nm and a distinctive star-like shape. The synthesized silver nano-particles (AgNPs) exhibited a dose-dependent anti-bacterial effect against some clinical bacterial isolates as multi-drug resistant (MDR), including Gram − ve bacteria such as Pseudomonas aeruginosa and Escherichia coli , as well as Gram + ve bacteria like Staphylococcus aureus and Streptococcus pneumoniae . The action can be ascribed to the unique biological and physicochemical features of AgNPs, which facilitate the disruption of bacterial cell membranes. The UV-visible analysis solution after the introduction of AgNPs indicated that the decrease in the absorbance peak of methyl red was attributed to the existence of silver nano-particles. Metal nano-particles can be synthesized using environmentally friendly processes and hold great potential for combating multi-drug resistant bacteria and degrading Azo dyes. Silver nano-particles (AgNPs) are synthesized with an extract derived from the algae Spirulina platensis, which is a sustainable and eco-friendly alternative.