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Interaction of brilliant cresyl blue and methylene green with DNA studied by spectrophotometric and voltammetric methods
Author(s) -
Liu Junli,
Li Jinghong,
Dong Shaojun
Publication year - 1996
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.1140080818
Subject(s) - methylene blue , chemistry , cationic polymerization , electrochemistry , dna , cresyl violet , tris , buffer solution , nuclear chemistry , binding constant , electrostatic interaction , adsorption , methylene , medicinal chemistry , chromatography , binding site , staining , organic chemistry , biochemistry , catalysis , electrode , medicine , photocatalysis , pathology , chemical physics
The binding behavior of two cationic dyes, brilliant cresyl blue (BCB) and methylene green (MG) to calf thymus DNA was studied by spectrophotometric and voltammetric methods. A red shift of the adsorption spectra and hypochromism accompany the binding of BCB and MG to calf thymus DNA. In 5 × 10 −2 mol dm −3 NaCl, 5 × 10 −3 mol dm −3 tris ‐ HCl pH 6.87 buffer solution, the apparent binding constants are: K BCB+ 3.0 × 10 4 M −1 ( N = 4.13) and K MG += 8.8 × 10 4 M −1 ( n = 4.44). Electrochemical studies show that the formal potentials shift negatively upon addition of DNA, indicating that the oxidized forms of the dyes have stronger affinity to DNA than the reduced ones. K BCB +/ K BCBH and K MG +/ K MGH are evaluated to be 10.39 and 7.04, respectively. Our investigation suggests that the two cationic dyes interact with DNA predominantly via electrostatic interaction.