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

TL;DR

This paper presents a simple method to create pH-responsive nanoprobes using modified glass nanopipettes, which exhibit pH-dependent ionic current rectification, enabling potential intracellular pH measurement.

Contribution

The study introduces a novel, facile fabrication technique for pH-sensitive nanoprobes based on ion current rectification in modified nanopipettes.

Findings

Modified nanopipettes show pH-dependent ionic current rectification.

The method enables potential intracellular pH sensing.

The approach is simple and effective for nanoprobe fabrication.

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.