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| We investigated the asymmetrical conductance behavior of a polymer based conical nanopore. The current rectification effect happened inside this negatively charged conical nanopore is influenced by the concentration and pH value of the electrolyte. Theoretical analysis and calculation based on Poisson-Nernst-Planck (PNP) equations were conducted to understand the mechanism of the asymmetrical conductance behavior. The difference in transmembrane current at opposite voltage bias is induced by the difference in ionic strength in external field. For pores with extremely tiny tip down to 2 nanometers, its rectification coefficients are particularly high. We attribute this effect to the overlap of the electrical double layer. In addition, we have also demonstrated the model calcium ions detector based on our conical nanopore system. It is sensitive to both pH values of the environmental solution and the concentration of the calcium ions presence, and, its resolution power is high. |
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| Keywords:conical nanopore, ion transport, ionic conductance, calcium ion detector |
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