▎ 摘　　要

NOVELTY - An electrode comprises a graphene-polypyrrole based composite attached at at-least part of a surface of the electrode, where the graphene-polypyrrole based composite is attached with one biological targeting moiety. USE - Electrode for use in electrochemical device for detecting a biological target in a sample, where biological target is antibody, an antibody derivative, a hapten, an antigen, a hormone, a protein, a polysaccharide, a lipid, a polynucleotide, a metabolite, thyroxine, triiodothyronine and thyroid stimulating hormone (all claimed). ADVANTAGE - The electrochemical device ensures quantitative detection of any of a combination of the thyroid stimulating hormone, the thyroxine and the triiodothyronine within 20 minutes, and improved sensitivity, reliability and specificity. The electrode has improved conductivity. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (1) an electrochemical device comprising one electrode defining a surface (2) a method for fabrication of a working electrode of an electrochemical device, which involves taking a working electrode, treating the working electrode with an agent capable of functionalizing a part of the surface of the working electrode to form a functionalized working electrode, incubating the functionalized working electrode with graphene-polypyrrole composite to form a surface modified working electrode, treating the surface modified working electrode with an agent capable of functionalizing a part of the surface of the graphene-polypyrrole composite and attaching one biological targeting moiety with the graphene-polypyrrole composite to realize the working electrode.