Premium
Electrooxidation of DNA at Glassy Carbon Electrodes Modified with Multiwall Carbon Nanotubes Dispersed in Chitosan
Author(s) -
Bollo Soledad,
Ferreyra Nancy F.,
Rivas Gustavo A.
Publication year - 2007
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200603782
Subject(s) - carbon nanotube , guanine , differential pulse voltammetry , chitosan , electrode , electrochemistry , glassy carbon , glutaraldehyde , materials science , cyclic voltammetry , nuclear chemistry , chemical engineering , dispersion (optics) , chemistry , nanotechnology , organic chemistry , nucleotide , biochemistry , physics , optics , engineering , gene
We report on the analytical performance of glassy carbon (GCE) electrodes modified with a dispersion of multiwall carbon nanotubes (CNT) in chitosan (CHIT) for the quantification of DNA. The electroanalytical response of the resulting electrodes was evaluated using differential pulse voltammetry, while the electrochemical reactivity of the film surface was characterized using scanning electrochemical microscopy. Different treatments of the modified GCE were evaluated to improve the stability of the film and the accumulation of DNA. The guanine oxidation signal of double stranded calf‐thymus DNA after 3‐min accumulation was 20 times higher at GCE/CHIT‐CNT cross‐linked with glutaraldehyde (GTA) than at bare GCE, while the peak potential was around 45 mV less positive. The guanine oxidation signal demonstrated to be highly reproducible, with 3.4% RSD for 5 different electrodes. The treatment with sodium hydroxide demonstrated to be not effective since the resulting films were less stable and the guanine oxidation signal was ten times smaller compared to electrodes prepared with the GTA treated films. The effect of chitosan molecular weight used to prepare the dispersion and the amount of carbon nanotubes dispersed were evaluated. The response of single stranded DNA and oligo(dG) 15 is also discussed.