Light as Trigger for Biocatalysis: Photonic Wiring of Flavin Adenine Dinucleotide-Dependent Glucose Dehydrogenase to Quantum Dot-Sensitized Inverse Opal TiO2 Architectures via Redox Polymers

Abstract

The functional coupling of photoactive nanostructures with enzymes creates a strategy for the design of light-triggered biocatalysts. This study highlights the efficient wiring of flavin adenine dinucleotide (FAD)-dependent glucose dehydrogenase (FAD-GDH) to PbS quantum dot (QD)-sensitized inverse opal TiO2 electrodes (IO-TiO2) by means of an Os-complex-containing redox polymer for the light-driven glucose oxidation. For the construction of IO-TiO2 scaffolds, a template approach has been developed, enabling the tunability of the surface area and a high loading capacity for the integration of QDs, redox polymer, and enzyme. The biohybrid signal chain can be switched on with light, generating charge carriers within the QDs, triggering a multistep electron-transfer cascade from the enzyme toward the redox polymer via the QDs and finally to the IO-TiO2 electrode. The resulting anodic photocurrent can be modulated by the potential, the excitation intensity, and the glucose concentration, providing a new degree...