Dendrimer-Au Nanoparticle Network Covered Alumina Membrane for Ion Rectification and Enhanced Bioanalysis.

Chen Wang,Fei-Fei Liu,Xiao-Ping Zhao,Xing-Hua Xia,Ju Li,Yuming Chen

doi:10.1021/acs.nanolett.9b05066

Abstract

Ion transport in an artificial asymmetric nanoporous membrane, which is similar to biological ion channels, can be used for biosensing. Here, a dendrimer-Au nanoparticle network (DAN) is in situ assembled on a nanoporous anodic aluminum oxide (AAO) surface, forming a DAN/AAO hybrid membrane. Benefiting from the high surface area and anion selectivity of DAN, the prepared DAN/AAO hybrid presents selective ion transport. Under a bias potential, a diode-like current–potential (I–V) response is observed. The obtained ionic current rectification (ICR) property can be tuned by the ion valence and pH value of the electrolyte. The rectified ionic current endows the as-prepared DAN/AAO hybrid with the ability of enhanced bioanalysis. Sensitive capture and detection of circulating tumor cells (CTCs) with a detection limit of 80 cells mL–1 as well as excellent reusability can be achieved.

Highlights

Ion transport in an artificial asymmetric nanoporous membrane, which is similar to biological ion channels, can be used for biosensing
A dendrimer-Au nanoparticle network (DAN) is in situ assembled on a nanoporous anodic aluminum oxide (AAO) surface, forming a DAN/AAO hybrid membrane
The symmetry breaking by covering DAN on one side of AAO endows the hybrid with an excellent ionic current rectification (ICR) property, ensuring highly sensitive cell detection

Summary

Introduction

Ion transport in an artificial asymmetric nanoporous membrane, which is similar to biological ion channels, can be used for biosensing. In comparison with the bare AAO, the DAN/ AAO hybrid film shows anion selective transport properties due to the existence of surface charges since only the redox current for the ferricyanide anion can be observed (Figure 2C).

Results

Conclusion