Machine Learning-Based Nanozyme Sensor Array as an Electronic Tongue for the Discrimination of Endogenous Phenolic Compounds in Food

• Published in: Analytical chemistry (Washington) Vol. 96; no. 40; pp. 16027 - 16035
• Main Authors: Jing, Wenjie, Yang, Yajun, Shi, Qihao, Wang, Yu, Liu, Fufeng
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 08.10.2024
• Subjects: Algorithms; analytical chemistry; Artificial neural networks; Benzidines - chemistry; bioactive properties; Biological activity; Black tea; Catalysis; catalytic activity; Copper - analysis; Copper - chemistry; Discriminant analysis; Electronic Nose; electronic tongue; Electronic tongues; Food; Food Analysis - methods; Fruit and Vegetable Juices - analysis; Fruit juices; grape juice; honey; Honey - analysis; Imines; Laccase; Laccase - chemistry; Laccase - metabolism; Machine Learning; mobile telephones; Nanostructures - chemistry; Neural networks; Neural Networks, Computer; Oxidation; Peroxidase; Peroxidase - chemistry; Peroxidase - metabolism; Phenolic compounds; Phenols; Phenols - analysis; Phenols - chemistry; prediction; Quinones; Reaction time; Sensor arrays; Sensors; Tea - chemistry; Vanillic acid; Vanillic Acid - analysis
• ISSN: 0003-2700; 1520-6882; 1520-6882
• DOI: 10.1021/acs.analchem.4c03586

The detection of endogenous phenolic compounds (EPs) in food is of great significance in elucidating their bioactivity and health effects. Here, a novel bifunctional vanillic acid-Cu (VA-Cu) nanozyme with peroxidase-like and laccase-like activities was successfully prepared. The peroxidase mimic behavior of VA-Cu nanozyme can catalyze 3,3′,5,5′-tetramethylbenzidine (TMB) to generate oxidized TMB (oxTMB). Owing to the high reducing power of EPs, this process can be inhibited, and the degree of inhibition increases with the increase of reaction time. Additionally, owing to the outstanding laccase mimic behavior of the VA-Cu, it can facilitate the oxidation of various EPs, resulting in the formation of colored quinone imines, and the degree of catalysis increases with the increase of reaction time. Based on the interesting experimental phenomena mentioned above, a six-channel nanozyme sensor array (2 enzyme-mimic activities × 3 time points = 6 sensing channels) was constructed, successfully achieving discriminant analysis of nine EPs. In addition, the combination of artificial neural network (ANN) algorithms and sensor arrays has successfully achieved accurate identification and prediction of nine EPs in black tea, honey, and grape juice. Finally, a portable method for identifying EPs in food has been proposed by combining it with a smartphone.