Microbial fuel cells (MFCs) harvest electrons from microorganisms in the anode and perform reductive reactions, such as the reduction of oxygen into water, in the cathode. Efficient electron harvesting is important in constructing high-performance MFCs; however, current methods for evaluating Coulombic efficiency (CE) consume large amounts of time, samples, and labors. A rapid quantification method to acquire CE of MFCs is presented in this study. The rapid quantification is accomplished by a laminar flow based microfluidic assay (LF-μAssay), which measures the open circuit voltage differences (ΔOCV) between active and inactivated microorganism samples. The ΔOCV measured by the microfluidic assay and the CE of lab-scale H-type microbial fuel cells were highly correlated. The linear correlation was validated with 3 pure strains of electrogenic microorganisms and applied on the evaluation of the CE of mixed-culture microorganisms with an error less than 0.053%.

微生物燃料电池（MFCs）从阳极中的微生物中收集电子，并在阴极中进行还原反应，例如将氧气还原成水。有效的电子收集对于构建高性能MFC非常重要。但是，当前评估库仑效率（CE）的方法会消耗大量时间，样本和人工。这项研究提出了一种快速定量方法来获取MFCs CE。快速定量是通过基于层流的微流体分析（LF-μAssay）完成的，该方法可测量活性和灭活微生物样品之间的开路电压差（ΔOCV）。通过微流分析测定的ΔOCV与实验室规模的H型微生物燃料电池的CE高度相关。