Characterization of Negative Differential Resistance in Asymmetric Nanopores Obtained from Two Soluble Electrolytes

[EN] Negative differential resistance (NDR) phenomena in nanofluidic diodes are characterized by a decrease in the electrical current with the increase in the transmembrane potential beyond a system-dependent threshold voltage. Here, we describe the NDR due to a nanoscale salt precipitation that occ...

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Bibliographic Details
Authors: Ramirez Hoyos, Patricio|||0000-0002-0067-4887, Portillo, Sergio, Mafe, Salvador, Siwy, Zuzanna S., Cervera, Javier
Format: article
Publication Date:2025
Country:España
Institution:Universitat Politècnica de València (UPV)
Repository:RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
Language:English
OAI Identifier:oai:dnet:riunet______::c21c19194f171e01685a340b68b4b624
Online Access:https://riunet.upv.es/handle/10251/233755
Access Level:Open access
Keyword:Negative differential resistance
Nanofluidic diodes
Salt precipitation
Conical nanopores
Current-voltage curves
Calcium ion sensing
Description
Summary:[EN] Negative differential resistance (NDR) phenomena in nanofluidic diodes are characterized by a decrease in the electrical current with the increase in the transmembrane potential beyond a system-dependent threshold voltage. Here, we describe the NDR due to a nanoscale salt precipitation that occurs in a conical nanopore in contact with two highly soluble salts in the external solutions. The new experimental design permits tunable and reproducible NDR effects that can be characterized from the I¿V curves for different pairs of soluble salts reacting at the pore tip to form the salt precipitate. The effects of pH and salt concentration on the precipitation, together with the use of electrolytes with different temperature-dependent solubilities, provide a complete description of the chemical NDR mechanism. In addition, the good reproducibility and stability observed over different voltage cycles suggest that the threshold potential needed for precipitation can be used for Ca2+ sensing in the range 1¿1000 mM.