A Taste Bud Organoid-Based Biosensor with a 3-Dimensional Microelectrode Array for Evaluating Caffeine's Impacts on...

Objective: The impact of caffeine on the gustatory system is still not fully understood. Therefore, it is highly essential to investigate caffeine's impacts on taste sensing. Impact Statement: The present study develops a taste bud organoid-based biosensor using a 3-dimensional microelectrode array to systematically investigate the modulatory effects of caffeine on various taste perceptions. Introduction: The integration of taste bud organoids with a 3-dimensional microelectrode array introduces a novel class of biomimetic taste sensors. This study utilizes this sophisticated sensor technology to systematically assess the responses of caffeine-treated taste bud organoids to a range of flavor stimuli. Methods: Biosensor functionality was assessed through metrics such as the proportion of responsive electrodes and signal-to-noise ratio. The electrophysiological characterization of the firing patterns was analyzed including firing rate and amplitude, in response to diverse flavor stimuli and caffeine exposure. Principal component analysis was employed to determine the sensor's efficacy in identifying and differentiating distinct flavor profiles. Results: The results indicate that the electrode response rate of the fabricated chip ranges between 45% and 56%, with signal-to-noise ratio values ranging from 20.71 to 23.62. Taste bud organoids exhibit distinct electrophysiological responses contingent upon the taste stimulus: sweet stimuli elicit the strongest response, followed by sour stimuli, whereas responses to bitter, salty, and umami stimuli approximate baseline levels observed prior to stimulation. Conclusion: This investigation enhances the understanding of caffeine's interaction with taste bud organoids, thereby contributing to the field of sensory biology and facilitating the advancement of sophisticated flavor sensing technologies.