Novel DNA Electrochemical Biosensor Using Anthraquinone-2-Sulfonic Acid Sodium Salt as Hybridization Indicator
A novel DNA biosensor based on layer-by-layer self-assembled multi-walled carbon nanotubes (MWNTs) functionalized with a mercapto group (SH-MWNTs) and gold nano-particles (GNPs) was presented, where anthraquinone-2-sulfonic acid sodium salt (AQMS) was used as hybridization indicator. The differential pulse voltammetry responses demonstrated that this DNA/GNPs/SH-MWCNTs/Au biosensor was enabled to specifically detect the single-base mismatch DNA sequence in phosphate buffer solution with pH 7.4 containing 0.3 mol/L Na+ and 1.0 mmol/L AQMS. The result showed that when the target DNA concentration was 1.0×10-10 to 1.6×10-5 mol/L, the cathodic peak current of Au electrode system with AQMS as indicator was linearly related to complementary NDA concentration, and the detection limit was about 3.82×10-11 mol/L and had good stability and specificity.
Tianbiao Zhang and Jerry Tian
M. Ma et al., "Novel DNA Electrochemical Biosensor Using Anthraquinone-2-Sulfonic Acid Sodium Salt as Hybridization Indicator", Advanced Materials Research, Vol. 298, pp. 56-62, 2011