Voltammetric Determination of 6-mercaptopurine at Co(III) Trisphenanthroline Complex and DNA Decorated with Grpahene Oxide Modified Glassy Carbon Electrode

摘要

A Cobalt (III) trisphenanthroline complex ([Co(phen)3] ) has been adsorption assembled on a glassycarbon electrode (GCE) modified with DNA decorated with graphene oxide (GO) by multiple sweepvoltammetry. In the present protocol, GO is served as a functional unit of DNA to greatly improve theefficient immobilization of DNA on the GC electrode and also offer a favorable microenvironment tokeep the DNA structure of double-stranded (dsDNA), which facilitates the intercalation of redox- active [Co(phen)3] . The evidences from scanning electron microscope, X-ray diffraction, cyclicvoltammetry, electrochemical impedance spectroscopy, emission spectroscopy and differential pulsevoltammetry reveal that [Co(phen)3] can be assembled on the surfaces of GO-decorated dsDNAdriven by electrostatic attraction, intercalation and -stacking interaction. Furthermore, the highlystable [Co(phen)3] /GO-dsDNA/GCE is used to the highly selective determination of 6- mercaptopurine (6-MP) in the human blood with satisfactory. The reduction peak current was linear to-8 -6 -86-MP concentration in the range from 510 to 210 M 6-MP, and the detection limit is 1.510 M(S/N = 3).