A Facile Strategy for the Ion Current and Fluorescence Dual-Lock in Detection: Naphthalic Anhydride Azide (NAA)-Modified Biomimetic Nanochannel Sensor towards H2S

I Wu,Xuanjun Zhang,Dan Zhang

doi:10.3390/chemosensors9110298

Abstract

Inspired by biological channels, the electric signal-based artificial nanochannel system exhibits high sensitivity in various analyses. However, ion current may be affected by many other factors, leading to false-positive signals. For reliable detection, in this work, we apply a facile strategy to combine both current signal and fluorescence. Fluorescent probes were conjugated to the nanochannel surface by covalent bonds. By utilizing the specific reduction of azide groups in the probe to amino groups by H2S, a synchronizing change in fluorescence and nanochannel surface charge was established. As a result, both transmembrane ion current and fluorescence intensity showed significant changes. The photoelectric double-checked locking from temporal and spatial variation validly confirmed the response process and protected detection accuracy. The work may provide new ideas for the development of more sophisticated current and fluorescence dual-index nanochannel systems.

Highlights

Ion channels in a biomembrane depend on electrical signal transduction to adjust and change cell behavior in response to external stimuli [1,2]
Artificial nanochannel sensors were developed by monitoring transmembrane ionic current [3,4,5,6,7,8,9,10,11,12,13]
Xia et al utilized the small aperture in the barrier layer of a nanochannel-ion channel hybrid to achieve ultrasensitive detection of thrombin protein [14]

Summary

Introduction

Ion channels in a biomembrane depend on electrical signal transduction to adjust and change cell behavior in response to external stimuli [1,2]. Xia et al utilized the small aperture in the barrier layer of a nanochannel-ion channel hybrid to achieve ultrasensitive detection of thrombin protein [14]. Xu and coworkers embedded ultra-small nanopipette into living cells, showing the capability for electrochemical monitoring of redox metabolism [17]. These existing nanochannels have achieved high recognition ability for specific targets, most sensors only consider individual temporal features from current signals

Methods

Results

Conclusion