Boosting the electricity generation of nonclassical electroactive microorganisms enabled by carbon dots

Producing electricity via microorganisms is promising as a sustainable and inexpensive energy source. However, most of the reported classical electroactive microorganisms are unusual in the environment, hindering their practical application. Here, we used carbon dots (CDs) to boost the power generation of common but nonclassical electroactive microorganisms, such as Escherichia coli and Staphylococcus aureus, in the natural environment. The CDs, which have good biocompatibility and high electron transfer efficiency, are taken up by bacterial cells and enable electrons to migrate rapidly to the ambient electrode because of the formation of robust electron transfer networks. The CDs promote electrochemical redox activity and increase the internal charge generation, and reduce the electrochemical impedance of the bacteria. As a result, the CDs facilitate rapid and high power generation in the microbial chemical cells and microbial fuel cells, with a nearly 94-fold and 172-fold improvement in current and power output compared with unmodified Escherichia coli. This work offers an important strategy for enhancing the generation of bioelectricity and facilitates the functional optimization of technologies that depend on microbial electron transfer.