▎ 摘　　要

NOVELTY - Field effect transistor chip comprises an insulating substrate and multi sensor units arranged on the insulating substrate, where each sensor unit comprises a drain electrode, a source electrode, a functional graphene layer, a single-stranded nucleic acid and a gate electrode, the drain electrode, where the source electrode and the functionalized graphene layer are located on the insulating substrate, the functionalized graphene layer is located between the drain electrode and the source electrode, the drain electrode, the source electrode and the functionalized graphene layer form a conductive channel, the single-stranded nucleic acid is fixed in the conductive channel, and gate is located in the conductive channel. USE - The field effect transistor chip is useful for detecting nucleic acid (claimed). DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) kit for detecting nucleic acid, comprising the field effect transistor chip, a guide RNA and a standard product containing the target nucleic acid, where the guide RNA has a nucleic acid sequence complementary to the target nucleic acid; and (2) detecting nucleic acid content, comprising preparing the standard product containing the target nucleic acid into multiple target solutions with different concentrations, adding multi target solutions of different concentrations and the sample to be detected respectively different sensor units of the kit for detecting nucleic acid, making the sample to be tested and the target solution with different concentrations in the different sensor unit to carry out guide RNA and reaction with Cas protein with trans-cleavage activity, and recording the signal variation of each sensor unit in a period of time, establishing a corresponding relationship between the concentration of the target nucleic acid and the corresponding signal change amount, where the guide RNA has a nucleic acid sequence complementary to the target nucleic acid, and according to the corresponding relation and the signal variation corresponding to the sample to be tested, calculating the content of the nucleic acid in the sample to be tested. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic representation of the partial sectional view of field effect transistor chip of the kit for detecting nucleic acid.