Tokyo Tech successfully develops highly sensitive graphene odor sensor using peptides
Tokyo Institute of Technology (Tokyo Institute of Technology) announced on February 2 that it has succeeded in detecting multiple odor molecules with high sensitivity using a “graphene odor sensor” that uses a self-assembled peptide film.
The result was the result of a research team consisting of graduate student Chihiro Homma, professor Mina Okouchi, and associate professor Yuhei Hayamizu of the Department of Materials Science and Engineering, Tokyo Institute of Technology. Details were published in the scientific journal “Biosensors and Bioelectronics”, which deals with biosensors and bioelectronics in general.
The development of technology to detect various odor molecules using highly sensitive “graphene field effect transistors” (GFET) is expected. In order to achieve high target selectivity that can discriminate specific odor molecules with high sensitivity, sensors using olfactory receptor proteins of living organisms have been realized so far. There was a problem that the operation became difficult. Therefore, methods of replacing the protein with a synthetic molecule that mimics the function of the protein are being investigated.
What the research team has been doing so far is to spontaneously adsorb to the graphite surface from a dispersed state in an aqueous solution, and through diffusion on the surface and interaction between peptides, self-organize into an ordered structure. This is the development and evaluation of peptides with the following characteristics. Among them, peptides that mimic silk proteins form β-sheet structures and form structurally stable self-assembled membranes on graphite surfaces. By immobilizing the peptide, which has an amino acid sequence that interacts with odor molecules, on the surface of graphene, which is a monolayer material, it is expected to realize a graphene sensor that is sensitive to odor molecules.
Therefore, in this research, we attempted to design three types of peptides to functionalize graphene: one type for molecular scaffolds and two types for probes. Using these peptides and GFETs, they aimed to detect three types of odor molecules that characterize the scent of plants.
The designed peptide has a molecular scaffolding domain containing repeating amino acid sequences of glycine and alanine. This domain has the characteristic of forming a β-sheet structure through intermolecular hydrogen bonding and stabilizing the molecular film on the graphite surface. In addition, this time, by conjugating a probe domain sequence that binds to odor molecules to this molecular scaffold sequence, it is assumed that a sensitive membrane that specifically interacts with odor molecules was constructed on graphene. In fact, it was confirmed that an ordered and uniform nanostructure was formed on the graphene surface.