Online Glucose Analysis System With High Precision and Wide Detection Range for Fermentation Monitoring

Online glucose monitoring during the fermentation process is critical for evaluating the microbial metabolism state and reaction course, achieving precise process control for industrial efficiency enhancement. However, the fast, wide-range and highly accurate test technique always presents a challenge for state-of-the-art analytical instruments. In this work, we proposed an online glucose analysis system based on a homemade screen-printed enzymatic biosensor chip composed of Prussian blue (PB) nanocubes with a high sensitivity of 83.404 mA
$\cdot $
mM
$^{-1} \cdot $
cm
$^{-2}$
. To match the detection behavior of this chip, a specific signal conversion system was designed to realize the highly precise acquisition and treatment of nA-level currents by integrating hardware acquisition circuits and Kalman filtering algorithms. Focusing on the continuous change in glucose concentration during fermentation, an adaptive injection strategy for the sampling volume was proposed to achieve an ultrawide linear range from 1 to 180 g/L. The results show that the online analytical system exhibits excellent detection performance with high accuracy and low relative error of detection (< 2%) during the fermentation of sophorolipid and ethanol compared to high-performance liquid chromatography (HPLC) and commercial analyzers.