Electrochemical insulin sensor based on complex tris(1-10, phenanthroline) cobalt (II) and multiwalled carbon nanotubes modified glassy carbon electrode

Modification of a glassy carbon electrode with multiwall carbon nanotube and a thin film of polyPoly[Co(Phen)3] was proposed as an electrochemical insulin sensor. For electropolymerization of Poly[Co(Phen)3]2+, 10 cyclic voltammetry were applied with scanning speed 0.5 V/S and range of potential -0.3 and 0.85 V relative to the reference electrode Ag / AgCl in phosphate buffer solution 0.05M, pH=4/7. The modified electrode showed an excellent selectivity and sensitivity toward insulin with a wide linear range 1.67-0.741 and 0.099-.654 µM and a very low detection limit of 8 nM. The proposed method is accurate, simple, cheap and could be used for determination of insulin in real samples such as blood samples.