摘要

The interaction of tyrosine (Tyr) with double stranded DNA was studied by cyclic voltammetry, fluorescence emission spectroscopy, and UV-vis spectroscopy. The presence of DNA on a single-walled carbon nanotubes (DNA/SWCNT/GCE) and multi-walled carbon nanotubes (DNA/MWCNT/GCE) modified glassy carbon electrode showed a decrease in the current and a positive shift in the Tyr oxidation peak, indicating the intercalative interaction. The transfer coefficient (alpha), heterogeneous rate constant (k(s)), and surface concentration (Gamma) were calculated in the absence and presence of DNA. The corresponding binding constant of Tyr with DNA and Hill coefficient were obtained from cooperative Hill model. The UV spectroscopic data confirmed the interaction between Tyr and DNA is intercalative with the binding constant of 3.98 x 10(3) mol(-1) L. Furthermore, the mechanism of fluorescence quenching has been discussed and the binding constant and numbers of binding sites were obtained as 3.37 x 10(3) mol(-1) L and 2, respectively from the Stern-Volmer plot.

  • 出版日期2014-3-5