玻璃纳米孔洞电极的制备及对环糊精单分子的检测  

Fabrication of Glass Nanopore Electrodes and Its Application in Single Molecule Detection of β-Cyclodextrin

作　　者：李国霞[1] 张志翔[1] 林祥钦[1] 

机构地区：[1]中国科学技术大学化学系,合肥230026

出　　处：《分析化学》2010年第12期1698-1702,共5页Chinese Journal of Analytical Chemistry

摘　　要：采用玻璃毛细管融封后打磨,直接得到了纳米孔洞玻璃电极。此电极洞壁厚实坚固,容易操作,电流噪声低,可实现对β-环糊精单个分子的检测。发现单个环糊精分子可以产生清晰分辨的两种幅度的电流脉冲,提出是环糊精在孔洞内的两种取向造成的。脉冲幅度与孔洞尺寸密切相关。在(10±5)nm的孔洞电极上可以得到2～5pA的响应脉冲。研究了电压大小与方向的影响,结果表明,电渗流对检测影响显著。在电渗流方向与环糊精扩散方向相反的条件下,100～600mV电极电位即可产生良好的脉冲信号,但平均脉冲宽度随电极电位的增大呈线先增大后减小的趋势,约在300mV电位下脉冲宽度最大。Nanopores are increasingly utilized as the tools for single-molecule detection.A new and simple way was developed to prepare nanopore electrodes by polishing the fused glass capillaries on sandpapers.The prepared nanopore electrodes can be used to detect single β-cyclodextrin molecule detection with high signalto-noise ratio,which was mechanically strong and easy to handle.Two clearly distinguishable current pulse amplitudes corresponding to the two orientations between β-cyclodextrin and pores were firstly found.Pulse amplitude was closely related to size of the pore,for example,2-5 pA response pulse can be gained with 10 ± 5 nm electrode.The analysis of applied electrode potential about values and directions showed that the electroosmosis flow has significant effects on detections.When the direction of electroosmosis was opposite to the one of diffusion gradient,the electrode can always produce excellent signals from 100 mV to 600 mV.The average pulse,however,showed a trend of first increase and then decrease,and reached the largest at the potential of about 300 mV.

关 键 词：玻璃纳米孔洞 孔洞电极 单分子检测 Β-环糊精 电化学 

分 类 号：O657.1[理学—分析化学]