Syntheses of zinc oxide and silicon oxide nanoparticles from microorganisms

• Grant number: 21/09310-9
• Support Opportunities: Regular Research Grants
• Start date: July 01, 2022
• End date: October 31, 2024
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Organic Chemistry
• Principal Investigator: Andre Luiz Meleiro Porto
• Grantee: Andre Luiz Meleiro Porto
• Host Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

Nanotechnology has been highlighted due to the fascinating properties of nanomaterials and their applications. Its obtainment is possible by physical, chemical and biological methods (plants and microorganisms). The search for ecologically benign and financially viable technologies has made possible the expansion of studies in the area of biosynthesis, since the other means of obtaining are more expensive and less sustainable to the environment. The synthesis of nanoparticles (NPs) through microorganisms, which is made possible by the intracellular and extracellular route, has made it possible to obtain materials with smaller sizes, better defined morphologies and better stability. Among the varieties of inorganic nanoparticles, ZnO is one of the materials that has received attention due to its specific properties and its applications in the electronics, health and personal hygiene industries, in pharmaceuticals, in food supplements in the animal industry, in paints and coatings, among others. Its research area is wide, as few microorganisms were discovered that are capable of efficiently synthesizing them, in addition to the need to develop an optimized protocol for obtaining them. Another nanomaterial that also attracts the attention of researchers are SiO2 NPs, due to their wide application in the field of nanoelectronics, photonics, optoelectronics and biotechnology. As a non-toxic nanomaterial and due to its biocompatibility, SiO2 NPs expand their application in biosensors, chemotherapy, bone tissue engineering, among others. As with ZnO NPs, the microorganisms used to obtain them are little explored. The present project aims to synthesize zinc oxide (ZnO) and silica (SiO2) nanoparticles through microbial machinery. Initially, a screening will be carried out with the strains of bacteria and fungi available in the Organic Chemistry and Biocatalysis Laboratory of the São Carlos Institute of Chemistry at USP. The microorganisms with the best ability to synthesize NPs will be used for a subsequent screening of precursors - zinc nitrate (ZnNO3)2, zinc chloride (ZnCl2), zinc acetate (ZnC4H6O4)2, potassium hexafluoro-silicate (K2SiF6), magnesium trisilicate (Mg2O8Si3) and sodium silicate (Na2SiO3), in order to check the most appropriate one(s). Then, the synthesis of NPs will be carried out, varying some parameters such as pH, temperature, precursor concentration and reaction time. The nanomaterials obtained will be characterized through Dynamic Light Scattering Analysis (DLS), Transmission Electron Microscopy (TEM) Analysis, Fourier Transform Infrared Spectroscopy (FT-IR), Ultraviolet-Visible Spectroscopy (UV-Vis), X-Ray Diffraction Analysis (XRD), Scanning Electron Microscopy (SEM) Analysis and Energy Dispersive X-Ray Spectroscopy (EDS) Analysis. (AU)