Preparation of glass fiber electrode for impedimetric DNA analysis and its application

In this study, carbon modified glass fiber from coal tar pitch was prepared with tube furnace under high temperature under nitrogen atmosphere. The carbonaceous material was converted to carboxylated carbonaceous materials via strong acid solution. The carboxylate terminated material was treated with carbodiimide and then converted to amide with 4-aminothiophenol. The materials was characterized with spectroscopic, electrochemical, microscopic and optical techniques. The –SH terminated material was self ordered with gold nanoparticles and capture-DNA (C-DNA) olgonucleotid sequence. The electrode was used in the determination of analyte (T-DNA for HIV-1) by electrochemical impedance spectroscopy (EIS). The linear equation for T-DNA was Rct = 0,7878[logC] + 11,8581 (R2: 0,9966) , with the linear range of 0,1 pM – 10 nM. The detection limits (S/N=3) was calculated as 0,013 pM. Precision and accuracy results of the developed method were studied. The influences of two different non-complementary sequence were studied. The values of charge transfer resistant change of the redox probe are approximately <1% and >-1.5%. In conclusion, it is not an important factor of interference effect of these sequences in the selected concentrations