Taste sensor, a useful tool which could detect and identify thousands of different chemical substances in liquid environments, has attracted continuous concern from beverage and foodstuff industry and its consumers. Although many taste sensing methods have been extensively developed, the assessment of tastant content remains challenging due to the limitations of sensor selectivity and sensitivity. Here we present a novel biomimetic electrochemical taste-biosensor based on bioactive sensing elements and immune amplification with nanomaterials carrier to address above concerns, while taking sweet taste perception as a model. The proposed biosensor based on ligand binding domain (T1R2 VFT) of human sweet taste receptor protein showed human mimicking character and initiated the application of immune recognition in gustation biosensor, which can precisely and sensitively distinguish sweet substances against other related gustation substances with detection limit of 5.1 pM, far less than that of taste sensors without immune amplification whose detection limit was 0.48 nM. The performance test demonstrated the biosensor has the capacity of monitoring the response of sweet substances in real food environments, which is crucial in practical. This biomimetic electrochemical taste-biosensor can work as a new screening platform for newly developed tastants and disclose sweet perception mechanism.
Combined dynamic tumor therapy of photodynamic therapy (PDT), sonodynamic therapy (SDT) and microwave dynamic therapy (MDT) can overcome the limitations of single reactive oxygen species (ROS)-based therapy (including limited tissue penetration depth and low ROS production). However, changes in the tumor microenvironment caused by ROS amplification and oxygen depletion induce severe immunosuppression at the tumor site, indicating effective immunosensitization of the tumors are urgently needed. Here, melanin-hematoporphyrin-chloroquine R837-hyaluronic acid (MHRH) nanoplatform that can simultaneously respond to 980 nm laser /1064 nm laser/ultrasonic/microwave was prepared for PDT/SDT/MDT, achieving outbreak of ROS in deep tumor. More importantly, the photothermal ablation and the participation of chloroquine R837 of MHRH NPs reversed the immunosuppression caused by oxygen depletion after ROS outbreak by promoting DCs maturation and secretion of macrophage exosomes. In summary, the natural MHRH nano-platform supplies an obvious anti-tumor “butterfly effect” through ROS outbreak, thermal ablation and significant immunosuppressive reversal, which provides a new and promising combined strategy of ROS-dynamic therapy and immune agonists in deep tumor tissues.