| 摘要 |
A DNA sensor is provided which is capable of identifying unknown DNA with enhanced detection sensitivity of the hybridization. A p-channel field-effect transistor having an electrolyte solution gate 8 and having as a p-channel 5 a diamond surface 2 which contains a mixture of at least a hydrogen-terminated surface and a surface terminated with an amino group or a molecule with an amino group is configured along with a probe DNA 11 constituted of a single-stranded DNA with known nucleotide sequence which is directly immobilized by a linker to the diamond surface 2 and with a target DNA constituted of an unknown single-stranded DNA which is dropped on the diamond surface 2. When the target DNA is in complementary relationship to the probe DNA 11, negative electric charge of the phosphate group of a double-stranded DNA produced by the hybridization of the probe DNA 11 with the target DNA both constituted of a single-stranded DNA is doubled, thereby resulting in increase of the hole density in the p-channel and shift of the threshold voltage of the p-channel field effect transistor toward positive direction. By detecting this shift of the threshold voltage toward positive direction, an identification can be made on whether or not the target DNA is in complementary relationship to the probe DNA 11. |
