Photobiocatalytic CO2 Reduction into CO by Organic Nanoparticle-Carbon Monoxide Dehydrogenase Assemblies: Surfactant Matters

CO2 reduction through semiartificial photosynthesis represents an attractive approach for conversion of solar light and abundant resources to value-added chemicals. Herein, designing highly efficient biocompatible photocatalysts that can boost CO2 reduction by the enzyme is desirable. In this work, biohybrid assemblies composed of a phenoxazine-based organic molecule (POZ-M) nanoparticular photosensitizer decorated with various surfactants and coupled with the nickel containing carbon monoxide dehydrogenase II from Carboxydothermus hydrogenoformans (CODH) are investigated. Organic nanoparticles that are decorated with CO2-responsive surfactant are capable of interaction with all components in the photocatalytic system. They increase the local CO2 concentration around the enzyme which renders a superior CO production rate of 1140 µmol g-1 h-1 that is two orders of magnitude higher than that for organic nanoparticles covered with PS-PEG-COOH surfactant.