(191o) Kinetics of Silver Cation Diffusion across an Algal Cell Wall during Silver Nanoparticle Biosynthesis | AIChE

(191o) Kinetics of Silver Cation Diffusion across an Algal Cell Wall during Silver Nanoparticle Biosynthesis


Mai, T. N. - Presenter, Lamar University
Rahman, A., Lamar University
Lin, J., Lamar University
Kumar, S. V., Lamar University
Jeffryes, C. S., Lamar University
Dahoumane, S. A., Yachay Tech University
In this study, the freshwater alga Chlamydomonas reinhardtii was used as a living biocatalyst to synthesize silver nanoparticles (AgNPs) and the effect of the Ag+ substrate concentration on diffusion into the cell, algal health and NP production rates were examined. Inorganic nanoparticles have attracted plenty of attention since their unique physicochemical properties, which can be utilized in wide range of fields including drug delivery, antibacterial applications, redox catalysis, biosensors, etc. Besides chemical synthesis, biosynthesis, a process where the desired product is converted within or with the assistance of living organisms, has been regarded as a potential process for inorganic NP synthesis which requires no chemical solvents, generates limited wastes and consumes comparably less energy. Among the platform of biosynthesized inorganic nanoparticles, the role of algae has been put in the spotlight and attracted increasing focus from scientists worldwide because of the sustainable nature thanks to requiring little more than metallic cation precursor, photons and CO2, However, the mechanisms and methods to optimize these processes remain undetermined. This research focuses on two primary process parameters. The first is the influence of the cell wall that per preliminary diffusion-reaction models indicates a bottleneck should occur. The second focus is on the Ag+/cell culture density ratio. Cultivations of C. reinhardtii (CC-1690) and its cell wall deficient strain (CC-4425), were carried out in a cultivation platform holding 36 mini photobioreactors. Silver Nitrate was the Ag salt added to the cell culture to produce the Ag+ ions for conversion to AgNPs by the algae. PAM fluorometry, UV-Vis spectroscopy and inductively coupled plasma atomic emission spectroscopy (ICP-AES) were applied to determine photosynthetic activity and silver composition in the liquid and solid phases of the cell culture. The current result has shown that high cell density to Ag+ ratios, even with high concentration of Ag+, can sustain the presence of silver nitrate and is potential to establish the sustainable photobioreactor system for the continuous production. Thus, this study can improve the development of low pollution, low cost, energy-saving processes for nanoparticles production by demonstrating the first steps toward a scalable photobioreactor-based production system for NP biosynthesis.