title: Simultaneous detection of guanine, adenine, thymine and cytosine at choline monolayer supported multiwalled carbon nanotubes film.
abstract: A rapid, convenient and accurate method for the simultaneous detection of guanine (G), adenine (A), thymine (T) and cytosine (C) was developed at a multiwalled carbon nanotube (MWCNT)/choline (Ch) monolayer-modified glassy carbon electrode (GCE). X-ray photoelectron spectroscopy data demonstrated that Ch was covalently immobilised on the surface of GCE through oxygen atom. The Ch monolayer provides a positively charged surface with -N(+)(CH(3))(3) polar groups, so that it can attract negatively charged MWCNTs to the surface. Consequently, the MWCNT/Ch film exhibited remarkable electrocatalytic activities towards the oxidation of G, A, T and C due to the advantages of high electrode activity, large surface area, prominent antifouling property, and high electron transfer kinetics. All purine and pyrimidine bases showed well-defined catalytic oxidation peaks at MWCNT/Ch/GCE. The peak separations between G and A, A and T, and T and C are 270, 200, and 190 mV, respectively, which are sufficiently large for their potential recognition and simultaneous detection in mixture. Under the optimum conditions, the designed MWCNT/Ch/GCE exhibited low detection limit, high sensitivity and wide linear range for simultaneous detection of G, A, T and C. Moreover, the proposed method was successfully applied to the assessment of G, A, T and C contents in a herring sperm DNA sample with satisfactory results.
authors.affiliation: School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou, PR China. wangpo@mail.ahnu.edu.cn
authors.forename: Po
authors.initials: P
authors.lastname: Wang
authors.forename: Hai
authors.initials: H
authors.lastname: Wu
authors.forename: Zong
authors.initials: Z
authors.lastname: Dai
authors.forename: Xiaoyong
authors.initials: X
authors.lastname: Zou
mesh_terms: D000225:Adenine / Q000032:analysis*; D000818:Animals; D002794:Choline / Q000737:chemistry; D003596:Cytosine / Q000032:analysis*; D004247:DNA / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000379:methods*; D005399:Fishes; D006147:Guanine / Q000032:analysis*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010084:Oxidation-Reduction; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013941:Thymine / Q000032:analysis*
chemical_list: D037742:Nanotubes, Carbon; D006147:Guanine; D003596:Cytosine; D004247:DNA; D000225:Adenine; D002794:Choline; D013941:Thymine