灿烂甲酚蓝电化学探针测定脱氧核糖核酸

Determination of DNA Using Brilliant Crystal Blue as Electrochemical Probe

运用电化学方法研究了灿烂甲酚蓝(BCB)与DNA的相互作用,并提出了以其为电化学探针测定DNA的方法.在pH 6.5的B-R缓冲溶液中,BCB在玻碳电极上有一对氧化还原峰,加DNA到BCB溶液中并在27℃恒温反应70 min后,溶液中没有新的氧化还原峰出现,而原有的BCB氧化还原峰电流降低,峰电位稍有负移,表明两者在该条件下生成一种非电化学活性的超分子化合物,导致溶液中游离BCB浓度降低,相应的峰电流降低.对结合反应的条件和电化学测定条件进行了优化,在最佳条件下,峰电流减小的程度与DNA浓度呈分段线性关系,由此建立了一种测定DNA的电化学分析方法,该方法的线性范围为8.00×10-7～6.00×10-5mol·L-1,应用于微量核酸试样的分析,结果令人满意.

An electrochemical investigation on the interaction of brilliant crystal blue (BCB) with DNA on glassy carbon electrode (GCE) was described and BCB was used as electrochemical probe for the determination of DNA. In Britton-Robinson (B-R) buffer solution of pH=6.5, BCB had a pair of redox peaks at -0.209 V and -0.222 V on GCE. After adding DNA to BCB solution at 27 ℃, there was no new peaks appeared, the peak currents of BCB decreased and the peak potential of BCB shifted slightly negatively. Under the reaction conditions, BCB reacted with DNA and formed an electrochemically inactive supramolecular compound. The binding conditions were optimized. Under the optimum conditions, there was a linear relationship between the decrease of the peak current of BCB and the concentration of DNA. The linear range of determining DNA was 8.00×10 -7 ～ 6.00×10 -5 mol·L -1. The purposed method was used to determine DNA in mixed samples and satisfactory results were obtained.