Hyaluronate-Functionalized Graphene for Label-Free Electrochemical Cytosensing.

Aihua Jing,Chenhuan Jing,Zhengshan Tian,Wenpo Feng,Gaofeng Liang,Chunxin Zhang

doi:10.3390/mi9120669

Abstract

Electrochemical sensors for early tumor cell detection are currently an important area of research, as this special region directly improves the efficiency of cancer treatment. Functional graphene is a promising alternative for selective recognition and capture of target cancer cells. In our work, an effective cytosensor of hyaluronate-functionalized graphene (HG) was prepared through chemical reduction of graphene oxide. The as-prepared HG nanostructures were characterized with Fourier transform infrared spectroscopy and transmission electron microscopy coupled with cyclic voltammograms and electrochemical impedance spectroscopy, respectively. The self-assembly of HG with ethylene diamine, followed by sodium hyaluronate, enabled the fabrication of a label-free electrochemical impedance spectroscopy cytosensor with high stability and biocompatibility. Finally, the proposed cytosensor exhibited satisfying electrochemical behavior and cell-capture capacity for human colorectal cancer cells HCT-116, and also displayed a wide linear range, from 5.0 × 102 cells∙mL−1 to 5.0 × 106 cells∙mL−1, and a low detection limit of 100 cells∙mL−1 (S/N = 3) for quantification. This work paves the way for graphene applications in electrochemical cytosensing and other bioassays.

Highlights

Studying intact living cells efficiently using electrochemical sensing systems has fundamental significance and practical importance in biotechnology, biological device design, drug discovery, molecular medicine, and disease diagnosis
When the cell was attached to the electrode, the change of the interface impedance was detected along the cell changes
Results and Discussion rd3ees.t1ue.rsFmpaebinnridecdeatdbioyinnaoPfHtBheSemCtooyctyootbsoetmnasineotrecre.lTl wsuospmeincrsoiolintewrsiothf a final concentration of 5.0 × 105 cells·mL−1, cell suspension were dropped on the hyaluronate-functionalized graphene (HG)/glass carbon electrode (GCE)

Summary

Introduction

Studying intact living cells efficiently using electrochemical sensing systems has fundamental significance and practical importance in biotechnology, biological device design, drug discovery, molecular medicine, and disease diagnosis. The current electrical nanostructured biointerfaces built of cytosensors have attracted considerable attention in measuring the expression of glycans on single cells [2] and immobilizing antibodies for rapid diagnosis [3], as it can clearly separate the surface bindings, quantify signals, and obtain a high sensitivity. Giaever group [5] designed a nanoscale gold electrode biosensor based on cell adhesion growth characteristics. Zhu groups [6] immobilized carboxymethyl chitosan-functionalized graphene for a label-free electrochemical impedance spectroscopy cytosensor and detected HL-60 cells by an electrochemical technique. There is still an increasing desire to develop new novel cytosensors for detection of cells with dimensional compatibility, high sensitivity, simplicity, selectivity, and low cost

Methods

Results

Conclusion