▎ 摘　　要

NOVELTY - Surface-enhanced Raman scattering and field-effect transistors (SERS-FET) double-mode biosensor comprises glass substrate indium tin oxide (ITO) conductive film, and gold nanoparticles (AuNPs) graphene sensing layer. The middle portion of the glass substrate is utilized as a channel. The upper surface of two sides of the glass substrate is covered with ITO conductive film. The tin indium oxide conductive film is covered with AuNPs graphene sensing layer. One side ITO conductive film is utilized as the source level. The other side ITO conductive film is utilized as the drain level. USE - SERS-FET double-mode biosensor for detecting microcystin-LR as a common toxin. ADVANTAGE - The SERS-FET dual-mode biosensor has simple operation, low cost, high sensitivity, selectivity and specificity and good safety performance. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) a preparation method for SERS-FET double-modebiosensor, which involves: (a) utilizing chemical vapour deposition method to prepare graphene on the metal substrate putting it into the etching liquid for etching cleaning the graphene thin film after etching the metal substrate; (b) transferring substrate on the two sides of the glass substrate coated with ITO conductive film taking graphene film as bridge using citrate; (c) reducing chloroauric acid to synthesize gold nano-particles AuNPs in the water phase obtaining a layer of array AuNPs film by oil water phase self-assembly mode; and (d) ransferring to the surface of the graphene forming AuNPs graphene sensing layer; and (2) a method for detecting microcystin-LR by SERS- FET double-mode biosensor, which involves: (a) taking AuNPs graphene ITO glass substrate as SERS substrate modifying MC-LR aptamer on the surface for capturing MC-LR molecule; (b) dripping MC-LR solution on AuNPs graphene ITO glass substrate using laser to obtaining the Raman spectrum of MC-LR; (c) realizing the qualitative detection of MC-LR; (d) taking AuNPs graphene ITO glass substrate as the substrate fixing the sample cell on the channel surface in the middle of the glass substrate; (e) adding the MC-LR solution into the sample cell; (f) inserting the gate into the sample cell to form the FET sensor the AuNPs graphene surface modified MC-LR aptamer for capturing MC-LR molecule; (g) the FET sensor is inserted into the electrode access circuit and the source-drain electrode through the probe station access detection circuit for MC-LR detection; and (h) realizing MC-LR quantitative detection.