Design Of A Gustative Tissue-Based Biosensor For Taste Analyzing

As one of the important sensations, taste can perceive and discriminate thousands of taste substances with high sensitivity and specificity, showing great potential commercial prospects in food safety, pharmaceutical industry, and environment monitoring. To achieve these goals, the electronic tongue systems, which mimic the biological taste working process, have been intensively studied in recent years. In biological taste system, the initial sensing organ lies in the taste epithelium. The isolated intact epithelium can well preserve the native taste receptor cell population, recognition units and primary microenvironment, and can be activated by taste stimuli. Therefore, the whole intact taste epithelium will be one of much better candidates for the sensitive elements of the gustative biosensor, as it preserves natural state of the taste buds and can be obtained easily. In this study, we combine the biological tissue with microelectrodes arrays (MEA) to establish a novel gustative tissue-based biosensor system for taste detection and evaluation.First of all, based on the signal perception and transduction process of taste receptor cells, we established a computational model of action potential in single taste receptor cell with MATLAB, simulating the responsive results to natural salt stimuli of NaCl solution with various concentrations as an example. Meanwhile, the electrophysiological activities of taste receptor cells in taste buds were measured through the multi-channel gustative tissue-based biosensor system with the stimulation of same salt stimuli. Both simulation and experiment results showed similar results in NaCl-induced potentials of taste receptor cells, which indicated the efficienct detection of the biosensor. Secondly, by this multi-channel recording method, we examined the electrophysiological activities of taste receptor cells in taste tissue to stimuli representing the basic taste qualities (sour, salt, bitter, sweet and umami). The signal responses were analyzed with different methods, aiming at discovering the perception and recognition mechanism of taste system. Then, in order to investigate the distinguishing feature of tissue bioelectronic tongue system, we applied the signal features to discriminate the basic taste response signals by principle component analysis (PCA) in the time domain. Finally, based on the recognition property of bioelectronic tongue, we recorded the signal responses of taste receptor cells to different substances and substance with different concentrations which all produce same basic taste, taking sweet perception as an example. Both natural sugars and artificial sweetner with certain concentrations gradiant were used to discover the evaluation characteristics of gustative tissue-based biosensor system.The recorded action potentials corresponding to different tastes displayed different spatiotemporal patterns. According to different analysis purpose, different methods were used to process the original responses. The simulation of action potentials in salt receptor cells verified the reliability and efficiency of the established bioelectronic tongue system, also revealing a dose-dependent increase in NaCl-induced potentials of taste receptor cells. The multi-channel analysis demonstrated the synchronizations of taste responses within the taste buds and revealed the activated subsets of taste receptor cells in different tastes perceptions, indicating the spatial segregation pattern in taste epithelium. These temporal characteristics were derived by time-domain and frequency-domain analysis, and the signals fired in different stimuli could be distinguished into different clusters by PCA. Finally, we managed to record and discriminate the extracellular potentials of the taste receptor cells in taste epithelium to different taste qualities with the MEA-tissue hybrid bioelectronic tongue and revealed the spatiotemporal information of early taste sensing. The study of MEA-tissue hybrid gustative biosensor broke through the limit of traditional electronic tongue and simulated the complex taste perception process, providing a new method of artificial taste study.