The application of bacteria-derived dehydrogenases and oxidases in the synthesis of gold nanoparticles

AbstractIn this work the green synthesis of gold nanoparticles (Au-NPs) using the oxidoreductive enzymesMyriococcum thermophilum cellobiose dehydrogenase (Mt CDH),Glomerella cingulata glucose dehydrogenase (Gc GDH), andAspergillus niger glucose oxidase (An GOX)) as bioreductants was investigated. The influence of reaction conditions on the synthesis of Au-NPs was examined and optimised. The reaction kinetics and the influence of Au ions on the reaction rate were determined. Based on the kinetic study, the mechanism of Au-NP synthesis was proposed. The Au-NPs were characterized by UV –Vis spectroscopy and transmission electron microscopy (TEM). The surface plasmon resonance (SPR) absorption peaks of the Au-NPs synthesised withMt CDH andGc GDH were observed at 535  nm, indicating an average size of around 50 nm. According to the image analysis performed on a TEM micrograph, the Au-NPs synthesized withGc GDH have a spherical shape with an average size of 2.83 and 6.63  nm after 24 and 48 h of the reaction, respectively.Key points• The Au NPs were synthesised by the action of enzymes CDH and GDH.• The synthesis of Au-NPs by CDH is related to the oxidation of cellobiose.• The synthesis of Au-NPs by GDH was not driven by the reaction kinetic.Graphical Abstract
Source: European Journal of Applied Physiology - Category: Physiology Source Type: research