摘要
通过金硫键将腺苷适配体互补链（S1）和末端带羧基的DNA链（S2）修饰在金纳米粒子（GNPs）表面,以及甲苯胺蓝（TB）与S2的酰胺反应将TB标记在金纳米粒子表面形成甲苯胺蓝标记的DNA探针分子TB-S2-GNPs-S1,然后在玻碳电极表面电沉积一层金纳米粒子,以其为载体将末端带有巯基的腺苷适配体（Apt）固定在电极表面,以牛血清蛋白为封闭剂消除非特异性吸附,再通过TB-S2-GNPs-S1中的S1与Apt杂交将TB-S2-GNPs-S1负载到电极表面,成功建立了一种以甲苯胺蓝为电化学探针检测腺苷的适配体生物传感器。采用紫外可见光谱和扫描电镜对合成的金纳米粒子和TB-S2-GNPs-S1复合物进行表征。对电极的组装过程采用循环伏安法和电化学阻抗法（EIS）进行表征,对传感器的性能采用差分脉冲法（DPV）和电化学阻抗进行研究。该传感器在1.0×10^-4-100.0 ng/m L范围内对腺苷具有良好的信号响应,相关系数（r）为0.994,检出限（S/N=3）为64.7 fg/m L。
In the paper,adenosine complementary aptamer strand（ S1） and carboxylic acid terminated DNA（ S2） were firstly modified on the gold nanoparticles（GNPs） surface through Au- S bonds.With the help of the amidation reaction of toluidine blue（ TB） and S2,TB was labeled on the surface of gold nanoparticles for the preparation of TB labeled DNA probe TB- S2- GNPs- S1. Then a layer of gold nanoparticles was electro-deposited on the glass carbon electrode surface,which was used as the immobilization matrix for adenosine aptamer with terminal mercapto group. Subsequently,bovine serum albumin（ BSA） as a blocking agent was used to eliminate non-specific adsorption. TB- S2-GNPs- S1 was immobilized on the electrode surface through the hybridization of S1 and the adenosine aptamer. An aptamer biosensor was constructed with toluidine blue as the electrochemical redox probe. The synthesized gold nanoparticles and TB- S2- GNPs- S1 composites were characterized by UV- Vis spectroscopy and scanning electron microscopy. The electrode assembly process was monitored by cyclic voltammetry and electrochemical impedance spectroscopy. The sensor＇s performance was studied by differential pulse voltammetry and electrochemical impedance spectroscopy. The sensor showed a linear relationship to adenosine from 1. 0 × 10- 4ng / m L to 100. 0 ng / m L,with a correlation coefficient（ r） of 0. 994 and a detection limit（ S / N = 3） of 64. 7 fg / m L.
出处
《分析测试学报》
CAS
CSCD
北大核心
2015年第4期395-400,共6页
Journal of Instrumental Analysis
基金
国家自然科学基金(21465012
21065004)
作者简介
通讯作者：杨绍明，博士，教授，研究方向：电分析化学及生物传感器，Tel：0791-87046336，E-mail：yangsm79@163．com
