摘要
将单壁碳纳米管(SWNTs)和十二醛(DA)混合超声分散,得到均匀、稳定的无机-有机纳米复合材料(SWNTs-DA)。将其滴涂在玻碳电极表面晾干得到复合材料修饰电极(SWNTs-DA/GCE),再通过胺醛缩合反应将末端修饰氨基的单链DNA探针共价固定在SWNTs-DA/GCE表面,构建了一种新型的DNA电化学传感器。以[Fe(CN)6]3-/4-为电活性探针,采用循环伏安法和电化学阻抗法对传感器的层层组装过程进行表征。以亚甲基蓝(MB)作为杂交指示剂,考察了传感器分析性能。实验结果表明,MB在传感器上的峰电流值(Ip)与互补序列浓度对数值(lgcS2)在1.0×10-15～1.0×10-10mol/L范围内呈良好的线性关系(r=0.998)。根据3倍信噪比(S/N=3),计算得检出限为2.0×10-16mol/L。选择性实验表明该传感器能对互补序列、三碱基错配序列和非互补序列进行很好的识别。
A uniform and stable inorganic -organic nanocomposite containing single-walled carbon nanotubes（SWNTs） and dodecyl aldehyde（DA） was obtained by ultrasonication method. The disper- sant was dropped on a glassy carbon electrode surface for dryness to get a modified electrode （SWNTs - DA/GCE）. Then the amino modified single-stranded probe DNA was covalenfly immobilized on SWNTs -DA/GCE by a facile amine -aldehyde condensation reaction, from which a novel DNA elec- trochemical sensor was constructed. The layer-by-layer assembly process of the biosensor was character- ized by cyclic vohammetry and electrochemical impedance spectroscopy using [ Fe（CN） 6 ] ^3-/4- ions as electroactive probes. The analytical performance of the biosensor was investigated through using methyl- ene blue（MB） as the hybridization indicator, and the results showed that the peak currents of MB on the biosensor had a good linear relationship with logarithm values of the target DNA concentrations （lgCs2） in the range of 1.0 × 10^-15 - 1.0 ×10^-10 mol/L（r =0. 998）. Based on three times of the sig- nal-to-noise ratio（S/N =3）, the limit of detection was estimated to be 2. 0 × 10^-16 mol/L. The selec- tivity experiments further showed that the complementary sequences, three-base mismatched sequences and the non-complementary sequences could be well distinguished by the biosensor.
出处
《分析测试学报》
CAS
CSCD
北大核心
2013年第4期414-419,共6页
Journal of Instrumental Analysis
基金
国家自然科学基金项目(21275127)
福建省自然科学基金项目(2011J01059)
"福建省高等学校新世纪优秀人才支持计划"项目(JA12204)
福建省重点高校资助项目(JK2011032)
