Direct electrochemistry of thermally denatured calf thymus DNA on a poly(methyl methacrylate)-graphite microcomposite electrode
Direct electrochemistry of thermally denatured calf thymus DNA on a poly(methyl methacrylate)-graphite microcomposite electrode
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DOI：
10.1039/c0an00485e
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发表时间：
2010-01-01
期刊：
影响因子：
4.2
通讯作者：
Chen, Guonan
中科院分区：
文献类型：
--
作者：
Dai, Hong;Lin, Yanyu;Chen, Guonan
研究了热变性小牛胸腺DNA在聚甲基丙烯酸甲酯-石墨粉微复合电极(PMMA/GME)上的直接电化学行为。结果表明，PMMA/GME复合电极由于其纳米界面的特性，对单链DNA的氧化有很大的促进作用。在PMMA/GME上观察到+1.04和+0.76V两个不可逆氧化峰，氧化电位负移，氧化电流(vs.Ag/AgCl)增大，对应于单链DNA分子中腺嘌呤和鸟嘌呤残基的氧化。因此，随后在PMMA/GME进行了单链DNA检测。在最佳条件下，鸟嘌呤或腺嘌呤残基的氧化峰电流与单链DNA的浓度在5.9×10(3)~1.1 mg mL(1)范围内呈良好的线性关系，检出限为1.0µg mL(1)。这种PMMA/GME具有制备简单、稳定性高、表面可再生、稳定性好、机械刚性好、电化学反应活性高等突出优点，为进一步设计DNA生物传感器提供了广阔的前景。
Remarkable direct electrochemical behaviors of thermally denatured calf thymus DNA (ssDNA) on the poly(methyl methacrylate)-graphite powder microcomposite electrode (PMMA/GME) were observed and investigated. The result indicated that the PMMA/GME showed great promotion of the electrochemical response towards the ssDNA oxidation due to the specific characteristics of the nanostructured interface on the resultant composite electrode. Two irreversible oxidation peaks at +1.04 and +0.76 V with obvious negative movement of oxidation potential and increase of the oxidation current (vs. Ag/AgCl) were observed on the PMMA/GME, which corresponded to the oxidation of adenine and guanine residues in the ssDNA molecules. Therefore, detection of ssDNA was then performed at the PMMA/GME. Under the optimal conditions, a good linear relationship was obtained between the oxidation peak currents of guanine or adenine residues and the ssDNA concentration in the range of 5.9 x 10(3) to ca. 1.1 mg mL (1) with a detection limit of 1.0 mu g mL (1). This PMMA/GME exhibits some outstanding advantages, such as ease of fabrication, high stability, renewable surface, excellent stability, mechanical rigidity and high electrochemical reactivity, which holds huge promise for further DNA biosensor design.