Electrochemical Sensing toward Noninvasive Evaluation of High-Starch Food Digestion via Point-of-Use Monitoring Glucose Level in Saliva

Abstract

To provide individuals with healthier and more reliable dietary recommendations for diabetic patients, a pragmatic electrochemical sensing toward in situ monitoring of glucose in saliva was designed for noninvasive evaluation of high-starch food digestion. The proposed sensor was constructed by exploiting a carbon-based nanostructure for electrical conductivity and Ni-based nanozyme toward direct catalytic oxidation of glucose for signal output. Particularly, the catalytic host–guest interaction between nanozyme and glucose was investigated to be a hydrogen bond via molecular docking, and the C11 and O5 sites in the glucose molecule were attacked during host–guest catalytic reaction through density functional theory (DFT) research. With merits of simplicity, sensitivity, and accuracy, the electrochemical sensor exhibited good performance for monitoring glucose with a detection limit of 10 μM (corresponding to 1.8 μg mL^–1). Moreover, it was well qualified to point-of-use trace glucose levels in saliva, offering a promising tool for noninvasive evaluation of high-starch food digestion (e.g., Wheat bread, Steamed bun, and Shao-mai) at different times after meals and eventually yielding benefits to dietary recommendations for diabetic patients.