Intracellular InP quantum dots facilitate the conversion of carbon dioxide to value-added chemicals in non-photosynthetic bacteria

Abstract

The semiconductor material with low bio-toxicity and broad light absorption region is crucial for semiconductor-bacteria photosynthetic biohybrid systems. Here we introduce the low-toxic InP/ZnSe/ZnS quantum dots (QDs) into the non-photosynthetic bacteria to produce value-added chemicals. The QDs with ideal biocompatibility act as the light-harvesting semiconductor in the photosynthetic biohybrid systems. The results indicate that the QDs can enter the interior of bacteria and effectively promote the conversion of CO2 to acetate. The electrons generated intracellular present the primary contribution in the conversion process compared with the extracellular electrons transferred through the electron mediator. The total productivity of photosynthesis products can reach ∼ 0.89 mmol·L−1·h−1 with a quantum efficiency (QE) of 6–8%. Assisted with the genetically engineered E.coli, the obtained acetate is then converted into a high-value-added product. The hybrid photosynthetic system that integrated the QDs and non-photosynthetic bacteria exhibits great potential for large-scale solar-to-chemical conversion applications and environmental protection.