Synthesis of Silver Nanoparticles Using Microalgae in the Multi-Vessel Reactor

摘要

This work proposes a novel multi-vessel reactor (MVR) to facilitate the synthesis of nanoparticles using microalgae. This equipment can hold up to 34 mini-photobioreactors (PBR), each provided with air flow to increase mixing and gas exchange and to keep the algae suspended. Silver nanoparticles (AgNPs) were produced in the MVR using the microalga Chlamydomonas reinhardtii. The experiments were carried out via three different routes: whole living cultures (WLC), exopolysaccharide-containing cell culture supernatant (EPS-S) and living cells that were washed to remove the EPS and resuspended in fresh media (LCFM). Surface plasmon resonance (SPR) excitation in the range of 400--430 nm confirmed the presence of AgNPs. AgNPs were produced by all three routes, but the particles tended to agglomerate with time. The morphological study revealed that the mean particle size of the AgNPs formed in the WLC route was 17.44 +/- 13.23 nm (n = 234). The reaction kinetics were compared to the kinetics from similar experiments in Erlenmeyer flasks. This comparative study revealed some significant advantages of the MVR system over the traditional flask system. The cell viability in WLC and LCFM cultures were characterized using Pulse Amplitude Modulated (PAM) fluorometry. The AgNP synthesis process was found to adversely affect the cell viability due to the cytotoxic effect of Ag+ and AgNPs.;Inorganic nanoparticles have many applications, including in therapeutics, catalysis, drug delivery, etc. Biosynthesis, as a low energy consumption and low pollution process, has been regarded as a potential process for producing unique types of inorganic nanoparticles. However, the mechanisms and methods to establish and optimize continuous, self-sustainable mass production remain undetermined. Thus, this research aims to move closer to mass production by proposing a MVR system that screens different process variables such as temperature, air-flow, photon input, etc.