基于金纳米粒子组装电化学DNA传感器检测p53抑癌基因的研究  

Electrochemical DNA Sensor for Determination of p53 Tumor Suppressor Gene Incorporating Gold Nanoparticles Modification

作　　者：罗贤文[1] 杜芳静[1] 吴烨[1] 高楼军[1] 李晓霞[1] 

机构地区：[1]延安大学化学与化工学院,延安716000

出　　处：《分析化学》2013年第11期1664-1668,共5页Chinese Journal of Analytical Chemistry

基　　金：陕西自然科学基础研究计划项目(No.2010JM2020)资助

摘　　要：基于金纳米粒子修饰金电极,构建了一种检测p53抑癌基因的非标记电化学DNA传感器.采用恒电位沉积法制备金纳米粒子,并将其修饰于电极表面制得金纳米粒子修饰金电极（GNPs/Au）.场发射扫描电镜用于金电极和金纳米修饰电极的表面形貌表征.5 ＇端带巯基的捕获探针DNA通过分子自组装法固定到GNPs/Au.传感器采用循环伏安法和电化学交流阻抗法表征.以亚甲基蓝为杂交指示剂,根据杂交前后吸附指示剂量的不同对p53抑癌基因进行定量测定.在优化的实验条件下,p53抑癌基因在1.0～1000 nmol/L浓度范围内与亚甲基蓝还原峰电流的变化值△I呈线性关系,检出限为0.8 nmol/L（S/N=3）.对50 nmol/L p53抑癌基因平行测定11次,相对标准偏差为3.8％.此传感器能有效区分完全互补序列、单碱基错配序列和三碱基错配序列DNA.A novel electrochemical DNA （E-DNA） on gold electrode for the determination of p53 tumor sensor was designed by incorporating gold nanoparticles suppressor gene. A modified gold electrode （GNPs/Au） was prepared by modifying the gold nanoparticles （GNPs） prepared by the in situ potentiostatic deposition method on the gold electrode surface. The surface topography of the gold electrode and GNPs/Au was characterized by field emission scanning electron microscope. The E-DNA sensor was prepared through the self-assembly of a 5＇-end thiolated probe DNA onto the surface of GNPs/Au followed by the hybridization of complementary sequence DNA. Cyclic vohammetry and electrochemical impedance spectroscopy were used to investigate each immobilization and hybridization step. By using methylene blue （MB） as an indicator for electrochemical hybridization detection, p53 tumor suppressor gene was quantitatively detected by differential pulse vohammetry （DPV） with the reduction peak current of MB. The increase in electrochemical signal upon hybridization was due to MB having a higher affinity for ds-DNA rather than ss-DNA. Under the optimal conditions, the reduction peak current of MB was linearly related to the concentration of p53 tumor suppressor gene from 1.0 to 1000.0 nmol/L with a detection limit of 0.8 nmol/L （ S/N = 3 ）. The relative standard deviation obtained was 3. 8%. The E-DNA sensor could differentiate the complete complementary DNA sequence, single-base mismatch DNA sequence and three-base mismatched DNA sequence, indicating a good selectivity.

关 键 词：非标记电化学DNA传感器 金纳米粒子 P53抑癌基因 

分 类 号：R318.6[医药卫生—生物医学工程] TB383.1[医药卫生—基础医学]