Preparation and Characterization of Gold Nanoparticles from Bacterial Source and Their Separation Using Low-Cost Zirconia Composite Membrane

In this work, the culture supernatant of Kocuria rhizophila BR-1 was used to synthesize gold nanoparticles (AuNPs). A transmission electron microscopy picture revealed that the produced nanoparticles (NPs) were spherical in form, with particle sizes ranging from 7 to 20 nm. The X-ray diffraction pattern revealed that the particles were crystalline in structure, with a characteristic peak for gold nanoparticles. Fourier transform infrared spectroscopy investigation exhibited the presence of many functional groups involved in the production of gold nanoparticles. The prepared gold nanoparticle is found to be possessed good antioxidant, anti-diabetic, and anticancer properties which is useful for various biomedical applications. Additionally, ultrafiltration was used to remove the synthesized gold nanoparticles from their aqueous solution. The permeate flux and particle rejection were measured to be 12.8 L/m²h and 60% at 207 kPa pressure and 100 mg/L feed concentration, respectively.