Enhanced hydrogen production by robust covalent biohybrid based on cell membrane specific click chemistry

The light-driven semiconductor-bacteria hybrid holds great potential for synthesis of diverse solar chemicals and fuels. However, the efficiency of electron transfer between biotic-abiotic interface often suffers from the insufficient robustness of biohybrid, which significantly imped its performance and applications. Here, a highly robust biohybrid was established by specifically and covalently grafting carbon quantum dots (CDs) onto bacterial cell membrane via the copper-catalyzed azide-Alkyne click (CuAAC) reaction. The formation of covalent bonds dramatically enhanced the robustness of hybrid and further shorten the distance of biotic-abiotic interface, endowing long-term stability under different conditions. Consequently, the cell membrane-specific covalent-biohybrid exhibited a 7.3-fold higher hydrogen production due to enhanced system stability, higher load of CDs on the cell surface and direct electron transfer efficiency. This work demonstrated a new and promising approach to improve the robustness and performance of photocatalytic semiconductor-bacteria hybrid system, which would further diversify the toolbox for solar chemicals/fuels production.