Fabrication and characterization of pH responsive nanoprobes based on ion current rectification

Abstract

In this study, we investigated the ionic current rectification of glass nanopipettes modified with bovine serum albumin - glutaraldehyde (BSA-GA) artificial membrane using solutions with various pHs. Ionic current rectification is a phenomenon that is observed with nanopores as asymmetric I-V curves, where the ionic currents recorded through a nanopore differ at the same magnitude of applied electrical potentials biased with opposite polarities. The results clearly showed that modifying the tip of a nanopipette results in a pH dependent ionic current behavior. The proposed strategy is a facile method for fabrication of a pH responsive nanoprobe that has a potential for intracellular pH measurement.