▎ 摘　　要

NOVELTY - Graphene microelectrode electrochemical test sensor comprises electrode, electrode area and gold wire, where the electrode area is composed of working electrode region (9), reference electrode area (10) and counter electrode area (8), where the working electrode area is provided with DNA molecular probe graphene microelectrode. USE - Graphene microelectrode electrochemical test sensor for detecting microRNAs (claimed). ADVANTAGE - The graphene microelectrode electrochemical test sensor has high throughput, rapid and convenient detection, has high sensitivity, high selectivity, and high accuracy. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) method for preparing graphene microelectrode with DNA molecular probe, which involves subjecting electrode conductive region of graphene electrode to plasma cleaning pretreatment, and modifying 5' end of DNA molecular probe with ferrocene molecule, using physical adsorption method, and fixing the DNA molecular probe on graphene microelectrode to obtain final product; and (2) a method for preparing graphene electrode, which involves cutting silicon wafer into 1-1.5cm length silicon chip, and then soaking into aqua regia, and washing with purified water for cleaning to remove silicon sheet surface dirt; depositing a layer of silicon dioxide by using chemical vapor deposition method to 600-1000nm to form silicon dioxide insulating layer, and then depositing the metal thin film on the silicon dioxide insulating layer through physical phase; stripping patterned into T-shaped chip substrate by photo-etching technology; using direct dry or wet transfer of 3-5 layers of graphene to surface of silicon dioxide insulating layer, graphene and T-shaped metal film at lower part of the contacting and covering 1-2mm, and then depositing 10nm silicon dioxide on the graphene layer, to form a passivation layer; and (3) using patterned passivation layer to expose side length of 0.1cm square ink as electrode conductive region. DESCRIPTION OF DRAWING(S) - The drawing shows the schematic view of graphene microelectrode electrochemical test sensor. Working electrode (2) Counter electrode (3) Counter electrode area (8) Working electrode region (9) Reference electrode area (10)