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The Effects of Tetramethylammonium Cation on Oligonucleotide Analysis with Aerolysin Nanopore
Author(s) -
Wu XueYuan,
Li MengYin,
Ying YiLun,
Long YiTao
Publication year - 2019
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.201901376
Subject(s) - aerolysin , tetramethylammonium , nanopore , oligonucleotide , chemistry , biophysics , electrolyte , nanotechnology , materials science , ion , biochemistry , biology , organic chemistry , dna , electrode , virulence , gene
Nanopore biosensors, as an extremely sensitive tool, are widely applied to single‐molecule analysis. Compared with the commonly used α‐hemolysin, aerolysin nanopore possess a narrower channel, which distributes the abundant charged residues in the lumen. We replaced the commonly used potassium cations (K + ) with tetramethylammonium cations (TMA + ) to explore the cation effects. Experimental results demonstrate that the blockage of oligonucleotides in the TMA + system is distinctly more considerable than that in K + system. In particular, the blockade currents of Poly(dA) 5 are very closed to 0 pA. In addition, the capture rate of oligonucleotides is distinctly increased, and it is speculated that amphipathic TMA + can enhance the affinity of aerolysin nanopore for oligonucleotides. Furthermore, the estimated effective charges ( Z inside ) of oligonucleotides inside aerolysin nanopore in two solutions suggest that the screening of K + on Poly(dA) 3 , Poly(dA) 4 , and Poly(dA) 5 is more effective than that for TMA + . This report deepens our understanding of the effects of cations in electrolyte.