Electrochemical studies of kanamycin immobilization on self-assembled monolayer and interaction with DNA

Abstract

The electrochemical characteristics of kanamycin onto self-assembled monolayer (SAM) modified gold electrode (SAM/Au) is investigated by cyclic voltammetry. In the potential range 0–0.6 V, Cu(II) yields a pair of stable redox waves at the bare gold electrode. E pa is located at 0.189 V and E pc at 0.254 V. In contrast, Cu(II) is reduced at a more positive potential and a decreasing current at the kanamycin SAM/Au electrode. Cu(II) and kanamycin can form a stoichiometry complex with chemical ratio of 2:1. The interaction of Cu(II)–kanamycin complex with calf thymus DNA is also studied in the solution. And the interactive mode between Cu(II)–kanamycin complex and DNA is verified by the fluorescence method. Binding constants ( K) of the Cu(II)–kanamycin complex to DNA and binding site size ( s) are calculated from voltammetric data and equal to 1.5 × 10 7 l/mol and 4 bp, respectively.