Green synthesis and characterisation of silver nanoparticles utilising a bioflocculant obtained from <i>Pichia kudriavzevii</i> isolated from kombucha tea SCOBY

Abstract

A Pichia kudriavzevii produced bioflocculant was used in the biosynthesis of silver nanoparticles (AgNPs). The generated Ag nanoparticles were given several analytical treatments to determine their properties. These techniques included transmission electron microscope (TEM), energy-dispersive X-ray spectroscopy (EDX), Fourier-transform infrared (FT-IR), transmission electron microscopy (TEM), scanning electron microscope (SEM), X-ray diffraction spectroscopy (XRD), thermogravimetric analysis (TGA), and UV–vis spectroscopy. The SEM scans showed particles that were smooth and nearly spherical in shape. EDX analysis showed the element silver with a percentage weight of 61.93% in addition to the elements present in the bioflocculant. Through FT-IR spectra functional groups for instance carboxyl, polyphenols, aromatics, alcohol, amine, and halo compounds were observed. The TEM picture displayed spherical particles that had a size range between 7 and 12 nm. TGA analysis revealed that AgNPs are thermally stable with over 85% mass retained at high temperatures, while the bioflocculant retained 60% weight after exposure to higher temperatures. UV–visible spectroscopy revealed an SPR band at 450 nm, while X-ray diffraction showed a crystallite size of 19 nm. Utilising bioflocculant as stabilising and coating agents in the biosynthesis of AgNPs is an ecologically safe technique that offers synthesis rates that are quicker and on par with chemical methods.