Ultrasensitive Biosensing Microchips to Control Ethanol Fermentation for Effectively Reducing Product Inhibition

The real-time and full concentration analysis of ethanol during the fermentation reaction could reduce product inhibition, thereby promoting productivity. However, only a few techniques can directly detect the fermentation broth without pretreatment. To address this issue, we proposed an ultrasensitive biosensing microchip to realize the precise determination of ethanol concentrations in the original fermentation broth, which relied on the construction of a Prussian blue (PB)/Au nanoflower architecture as the recognition probe. Since the in situ growth of the nanoflowers, a biosensing microchip was functionalized to accurately recognize the ethanol within only 9 s. Using this biosensor to monitor and control the ethanol concentration in the whole 109 h fermentation production, the ethanol yield has been increased from 47.1% to 50.09%, and the average fermentation time has been reduced from 44 to 27.25 h to successfully cut down the product inhibition during the whole industrial fermentation process.