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Abstract Much effort in the field of nanopore research has been directed toward reproducing the efficient transport phenomena of biological ion channels. For synthetic nanopores to replicate channel function on the scale of a cellular membrane, it is necessary to consider the modes of crosstalk between channels as well as to develop approaches to prepare nanopore arrays consisting of pores with different transport properties, akin to a membrane in an axon. In this manuscript, first ion concentration polarization (ICP) is identified as the primary means of the crosstalk, and subsequently, the extent and degree of ICP is tuned via targeted chemical modification of the pore walls’ functional groups. Next, two fabrication methods of a model two‐nanopore array are presented in a silicon nitride membrane in which one nanopore contains a bipolar ionic junction and functions as an ionic diode, while the other one is a homogeneously charged ionic resistor. The targeted chemical modification of a thin gold layer at the opening of one pore in an array that leaves the other pore located a few tens of nm away, unmodified, is utilized. These results provide an important framework for designing abiotic ionic circuits that can mimic physiological multichannel ion transport and communication.
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Ion Concentration Polarization Tunes Interpore Interactions and Transport Properties of Nanopore Arrays
Abstract Biological processes require concerted function of many channels embedded in the cell membrane. While single solid‐state nanopores are already designed to mimic properties of individual biological channels, it is not yet known how to connect the pores to achieve biomimetic ionic circuits with interacting components. To identify fundamental processes that control interactions between nanopores embedded in the same membrane, a model system of minimal arrays consisting of two and three nanopores in silicon nitride films is designed. The constituent nanopores have an opening diameter <10 nm, and the interpore spacing is tuned between 15 and 200 nm. The experimental and modeling results reveal that nanopores in an array interact with each other via overlapping depletion zones created by the process of concentration polarization. The interactions can be further controlled by salt concentration and voltage. These results showcase a possibility of tuning interactions between nanopores and transport properties of arrays by chemical modification of the pore walls. Arrays consisting of nanoporous ionic diodes feature depletion zones with higher concentrations, and lower current suppression than homogeneously charged pores. These experiments and modeling provide the first steps to leave the constraints of single nanopores and to design biomimetic ionic circuits.
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- Award ID(s):
- 2200524
- PAR ID:
- 10485137
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Functional Materials
- Volume:
- 34
- Issue:
- 11
- ISSN:
- 1616-301X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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