DNA-based immobilization for improved electrochemical carbon dioxide reduction

Electrochemical reduction of carbon dioxide (CO2) is a promising route for the up-conversion of this industrial by-product. However, to perform this reaction with a small-molecule catalyst, the catalyst must be proximal to an electrode surface. Efforts to immobilize these catalysts on electrodes have been stymied by the need to optimize immobilization chemistries on a case-by-case basis. As with many reactions, Nature has evolved catalysts with high specificity, selectivi-ty, and activity. By taking inspiration from biological porphyrins and combining it with the specificity of DNA hybridiza-tion, we have developed an improved electrocatalyst platform for CO2 reduction. The addition of single-stranded DNA to the porphyrin-based catalysts improved their stability, and DNA-catalyst conjugates were immobilized on screen-printed carbon electrodes using DNA hybridization with nearly 100% efficiency. Increased turnover frequency (TOF) and catalyst stability were observed with the DNA-immobilized catalysts as compared to the unmodified small molecules. This work demonstrates the importance of taking inspiration from Nature and demonstrates the potential of DNA hybridization as a general strategy for molecular catalyst immobilization.