Abstract

Concentration of carbon dioxide (CO₂) in the atmosphere has increased significantly due to anthropogenic activities and attributed as a major factor to global warming. Its detection by biosensing methods will provide an alternative for the assessment of CO₂ concentration. Biomineralization of CO₂ is one of the available methods for the biological conversion of CO₂ to carbonate using a highly active enzyme, carbonic anhydrase II (CAII). CAII was used for the carbonation reaction to convert CO₂ to CaCO₃. The precipitation of calcium carbonate (CaCO₃) was promoted in the presence of the CAII at 325 K. CAII showed an enhanced formation of solid CaCO₃ through the acceleration of CO₂ hydration rate at 325 K. Furthermore, the electrocatalytic properties of glassy carbon electrode enable us to determine the reduction peak potential values of CO₂ through cyclic voltammetry at –1.75 and 0.3 V at 325 K. Molecular dynamic (MD) simulations were performed each at 50 ns time scale provided a deeper insight into the molecular basis of the CAII interaction with CO₂ at different temperatures, highlighted that the CAII can detect CO₂ up to 325 K. We assume that CAII could be an effective and economical biosensor for biomineralization of CO₂ at high temperature 325 K.

Keywords: Carbon dioxide sequestration; Calcium carbonate; Biomineralization; MD simulations; Carbonic anhydrase II