On current blockade upon analyte translocation in nanopores

• Published in: Journal of applied physics Vol. 129; no. 6
• Main Authors: Wen, Chenyu, Zhang, Shi-Li
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 14.02.2021
• Subjects: Algorithms; Amplitudes; Applied physics; Data analysis; Electrohydrodynamics; Electrokinetics; Electroosmosis; Mathematical analysis; Mathematical models; Porosity; Resistance; Waveforms
• ISSN: 0021-8979; 1089-7550; 1089-7550
• DOI: 10.1063/5.0035113

Nanopore sensing primarily concerns quantifying the amplitude and shape of blockage current as well as the frequency of translocation events by analyzing the variation of the ionic current upon analyte translocation in a nanopore that represents an extremely simple device structure. To facilitate such an analysis, most reported physical-phenomenological models focus on geometrical factors. Here, we systematically analyze several other factors that may influence the amplitude and waveform of the blockage current. Our theoretical analysis starts with an analytical model based on geometry. It is then extended to include effects of surface conductance, electroosmotic flow, ionic concentration polarization, and induced charge on nanopore membranes. This approach allows for the examination of related electrokinetic and electrohydrodynamic aspects of analyte translocation in nanopores. The model results are confirmed using numerical simulation. The principal outcome of our theoretical scrutiny includes the identification of the respective determinatives of various factors as well as criteria for safely neglecting some of them when correlating the amplitude and waveform of blockage current to the properties of the translocating analyte. Our attempt to categorize these factors can be of practical implications in understanding the translocation process and for developing advanced data analysis algorithms as an effort to promote nanopore sensor applications.