A microbial protein-assisted silica ball comprising of silica-nanoparticles with plausible optical properties for multiple applications

Abstract

Background: Production of mesoporous silica nanoparticles and its conceivable applications in the fields of chromatography, surface polishing, catalysis and drug delivery etc. has gained momentum recently. We demonstrate here an efficient methodology for the amicable synthesis of silica balls consisting of mesoporous silica nanoparticles (SiO 2 -NPs) by using a secretary protein (bioremediase). The protein was isolated from a thermophilic non-pathogenic bacterium BKH1 (GenBank Accession No. FJ177512). Methods: Silica ball was formed at ambient temperature by mixing the dissolved bacterial protein dropwise to an organic precursor tetra-ethyl-orthosilicate (TEOS) solution at neutral pH environment. Surface morphology and compositional studies of prepared silica ball were carried out by using High-Resolution Transmission Electron Microscope (HRTEM) and Field Emission Scanning Electron Microscope equipped with Energy Dispersive X-ray Analyzer (FESEM-EDX). Fourier Transform Infrared Spectroscopy (FTIR) and X-ray diffraction (XRD) studies were further carried out for auxiliary characterization to determine the nature of SiO 2 -NPs. Stability of the as prepared SiO2-NPs was determined by noting the Zeta potential (ζ). The dye degradation activity of the silica balls was noted against different dyes. Results: Silica ball thus formed consisted of silica nanoparticles whose average dimensions were 20 ± 10 nm (n = 100). The size of the silica ball and also the sizes of the constituents' nanoparticles depend on the protein concentration in the reaction mixture. The result of zeta potential implied the moderate stability of SiO 2 -NPs at neutral pH environment. The SiO 2 -NPs showed green fluorescence emission which might have feasibly applications in the field of biomedical imaging. The decolourizing effect of silica ball on various dyes is a cost effective phenomenon as it can be used repeatedly. Conclusion:The pr otein-assisted silica balls preparation has a special consequence as it is an environmentally benign, lucrative and one pot synthesis approach which could be used repeatedly for various biomedical and chromatographic packing purposes.