Investigation of Single-stranded Deoxyribonucleic Acid Translocation Through α-Hemolysin Nanopore with Ionic Liquid Supporting Electrolytes
10.11895/j.issn.0253-3820.171404
- VernacularTitle:离子液体电解质对DNA穿过α-溶血素纳米孔的影响
- Author:
Shan-Shan SUN
1
;
Yuan-Min LIU
;
Guang-Yu LI
;
Zhi-Yong WU
Author Information
1. 东北大学理学院分析科学研究中心
- Keywords:
Single nanopore;
α-Hemolysin;
Single-stranded DNA;
Ionic liquid
- From:
Chinese Journal of Analytical Chemistry
2018;46(6):858-864
- CountryChina
- Language:Chinese
-
Abstract:
Due to the difference in spatial configuration and charge of the bases in a DNA molecule, characteristic translocation current pulses through a single nanopore could be obtained. This could become the basis of DNA sequencing method. However, due to the fast translocation speed (sub-micro seconds) and the small current change (about pA), it is still a challenge to obtain the accurate molecular substructure with present electronic techniques. In this work, in order to control the translocation behavior of ssDNA, two kinds of ionic liquids with high viscosity and conductivity were introduced to establish a viscosity gradient with the α-hemolysin single nanopore interface and the acidity of the solution was optimized. The trans chamber contained pure BmimPF6 and the cis chamber contained 1 mol/ L BmimCl and 10 mmol/ L Tris-HCl ( pH 5. 5 ). Preliminary experiment results under this electrolyte configuration showed that poly ( dC) 15 , poly ( dC) 15 , poly(dC) 30 and poly(dC) 50 exhibited obvious long duration pulses with high current suppression ratio. The blocking depth reached more than 95％ of long blocking events. The duration time of long blocking events prolonged to tens or hundreds of milliseconds. Meanwhile, the peak-peak of baseline noise was reduced by about 30％ .
