"Chemical-pain sensor" based on nanovesicle-carbon nanotube hybrid structures.

We developed a "chemical-pain sensor" that could recognize chemical pain stimuli such as capsaicin and resiniferatoxin just like mammalian chemical pain sensory systems. Here, we first prepared nanovesicles containing rat pain sensory receptor, rat transient receptor potential vanilloid 1 (rTRPV1), which is activated by noxious heat and capsaicin. And the nanovesicles were immobilized on a single-walled carbon nanotube-based field effect transistor. The chemical-pain sensor could selectively detect chemical pain stimuli with a high sensitivity of a 1 pM detection limit. It also responded to different chemical pain stimuli in a manner similar as to that of mammalian chemical pain sensory systems. This sensor platform can be utilized for various practical applications such as food screening tools and artificial somesthetic sensors. Moreover, TRP families have been suggested as potential drug targets related to nerve and circulation disorders. Thus, the capability of monitoring TRP responses using our sensor platforms should provide a powerful means for the development of new drugs as well as the basic research about nerve and circulation systems.