A Biomimetic Nanofluidic Tongue for Highly Selective and Sensitive Bitter Perception

Precise detection of bitter compounds is crucial for enhancing life quality, ensuring food safety, and improving pharmaceutical efficacy. However, the structural diversity of bitter compounds often limits detection specificity and sensitivity. Inspired by the human taste perception mechanism, we have developed a biomimetic nanofluidic tongue based on bitter receptor-integrated nanochannels for the highly selective and sensitive perception of bitter molecules. This hybrid platform is constructed by leveraging T2R38 receptor as a model protein to chemically modify the nanochannel surfaces, enabling a sensitive recognition of specific bitter molecules in a wide linear detection range from 10-4 M to 0.1 pM. An ultralow detection limit of 0.018 pM is achieved for structurally diverse bitter molecules, including allyl isothiocyanate, yohimbine hydrochloride, and limonin. The sensor remains stable at 4°C for a week and is reusable. Additionally, it has also been successfully applied to detect bitter limonin in spoiled orange juice. This artificial bitter sensor holds significant potential in the food and beverage industries, pharmaceuticals, and humanoid robots, and provides valuable insights for the design of future bitter sensors.