(386d) Synthesis of Silver Nanoparticles Using Extracelluar Polymeric Substances from Cosmarium SP. Using Microwave

In this study, we have developed a novel microwave-assisted method by using extracellular polymeric substances (EPS) from a freshwater microalga, Cosmarium sp. to produce silver nanoparticles (AgNPs). We have designed a process to extract the EPS from the microalgae. The applications of AgNPs include, but are not limited to, biomimetic platforms, biomarkers and optoelectronic devices. The use of microwave as an energy source to judiciously drive AgNP synthesis and bio- reduction, as opposed to traditional methods, diminishes the inimical effect of toxic chemicals. The synergistic use of microwave with algal EPS for the bio-reduction of inorganic nanoparticles is not well studied, but it may lead to an efficient, scalable, “green” platform for the synthesis of inorganic nanoparticles. However, the underlying mechanisms for this process need to be studied. We measured the effect of EPS on the production of AgNPs, and characterized it using HPLC and rheology. The stability, crystallinity, shape and size of AgNPs were characterized using UV-vis spectrophotometry, X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). In addition to the characteristic change in color, the formation of AgNP was validated by the SPR band in the range of 425-435 nm and by their XRD pattern having 2θ peaks at 38^°, 44^°, 64^° and 77^°. The AgNP colloid showed a more intense SPR band and was faster to obtain as compared to other green syntheses routes. The formed AgNPs were stable over a long period. The prospective applications in the field of biotechnology and material science will be considered through formation of different shaped metallic nanoparticles with specific functions, as well as the potential of applying cell culture technologies to the field of nanomaterial production.