title: Ordered mesoporous carbon modified carbon ionic liquid electrode for the electrochemical detection of double-stranded DNA.
abstract: In this paper the direct electrochemistry of double-stranded DNA (dsDNA) was investigated on ordered mesoporous carbon (OMC) modified carbon ionic liquid electrode (CILE). CILE was prepared by mixing graphite powder with 1-ethyl-3-methylimidazolium ethylsulphate ([EMIM]EtOSO(3)) and liquid paraffin. A stable OMC film was formed on the surface of CILE with the help of Nafion to get a modified electrode denoted as Nafion-OMC/CILE. Due to the specific characteristics of OMC and IL present on the electrode surface, the fabricated electrode showed good electrochemical performances to different electroactive molecules. The electrochemical responses of dsDNA were carefully investigated on this electrode with two irreversible oxidation peak appeared at +1.250 V and +0.921 V (vs. SCE), which was corresponding to the oxidation of adenine and guanine residues in dsDNA structure. The electrochemical behaviors of dsDNA were carefully investigated on the Nafion-OMC/CILE. Experimental results indicated that the electron transfer rate was promoted with the increase of the oxidation peak current and the decrease of the oxidation peak potential, which was due to the electrocatalytic ability of OMC on the electrode surface. Under the optimal conditions the oxidation peak current increased with dsDNA concentration in the range of 10.0-600.0 microg mL(-1) by differential pulse voltammetry (DPV) with the detection limit of 1.2 microg mL(-1) (3sigma).
authors.affiliation: Institute of Nano-Science and Technology Center, Huazhong Normal University, Wuhan 430079, PR China.
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Zhu
authors.forename: Xia
authors.initials: X
authors.lastname: Li
authors.forename: Yan
authors.initials: Y
authors.lastname: Zeng
authors.forename: Wei
authors.initials: W
authors.lastname: Sun
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D002244:Carbon / Q000737:chemistry*; D003217:Conductometry / Q000295:instrumentation*; D004247:DNA / Q000032:analysis* / Q000737:chemistry*; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D052578:Ionic Liquids / Q000737:chemistry*; D016062:Porosity; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D052578:Ionic Liquids; D002244:Carbon; D004247:DNA