Electrochemical Impedance Characterization of Cell Growth on Reduced Graphene Oxide–Gold Nanoparticles Electrodeposited on Indium Tin Oxide Electrodes

Somasekhar Chinnadayyala,Sungbo Cho,Jinsoo Park,Ajay Yagati,Jae-Hee Han,Yonghyun Choi

doi:10.3390/app9020326

Somasekhar Chinnadayyala, Sungbo Cho + Show 4 more

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https://doi.org/10.3390/app9020326

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Journal: Applied Sciences	Publication Date: Jan 17, 2019
Citations: 8	License type: CC BY 4.0

Affiliation: Gachon University, Chung-Ang University

Abstract

The improved binding ability of graphene–nanoparticle composites to proteins or molecules can be utilized to develop new cell-based assays. In this study, we fabricated reduced graphene oxide–gold nanoparticles (rGO-AuNP) electrodeposited onto a transparent indium tin oxide (ITO) electrode and investigated the feasibility of the electrochemical impedance monitoring of cell growth. The electrodeposition of rGO–AuNP on the ITO was optically and electrochemically characterized in comparison to bare, rGO-, and AuNP-deposited electrodes. The cell growth on the rGO–AuNP/ITO electrode was analyzed via electrochemical impedance measurement together with the microscopic observation of HEK293 cells transfected with a green fluorescent protein expression vector. The results showed that rGO–AuNP was biocompatible and induced an increase in cell adherence to the electrode when compared to the bare, AuNP-, or rGO-deposited ITO electrode. At 54 h cultivation, the average and standard deviation of the saturated normalized impedance magnitude of the rGO–AuNP/ITO electrode was 3.44 ± 0.16, while the value of the bare, AuNP-, and rGO-deposited ITO electrode was 2.48 ± 0.15, 2.61 ± 0.18, and 3.01 ± 0.25, respectively. The higher saturated value of the cell impedance indicates that the impedimetric cell-based assay has a broader measurement range. Thus, the rGO–AuNP/ITO electrode can be utilized for label-free and real-time impedimetric cell-based assays with wider dynamic range.

Highlights

Graphene-based nanomaterials have garnered much attention when it comes to sensors as they require enhanced measuring sensitivity and functionality due to their unique electrochemical, mechanical, and optical properties [1]
The results indicated that the HEK293/GFP cells adhered and grew more efficiently on the reduced graphene oxide (rGO)–AuNP-deposited indium tin oxide (ITO) electrode when compared to the bare AuNP- or rGOdeposited ITO electrode
An rGO–AuNP-deposited ITO electrode was fabricated to be used as an advanced impedimetric cell sensor with a wider dynamic range

Summary

Introduction

Graphene-based nanomaterials have garnered much attention when it comes to sensors as they require enhanced measuring sensitivity and functionality due to their unique electrochemical, mechanical, and optical properties [1]. Graphene oxide (GO)-deposited electrode sensors have been used in the ultrasensitive detection of proteins and living microorganisms [2,3,4]. Sci. 2019, 9, 326 the sensitivity and selectivity of the sandwich-type electrochemical immunosensor [5], the cell signaling-protein sensor [6], or apoptotic cell sensor [7]. The hybrid material of graphene anchored with nanoparticles gives rise to synergetic effects such as encouraging biocompatible conditions [8] or increasing the electrochemical sensing area of its tangled construction [9]. Graphene–nanoparticle composites along with electrochemical measurement showed great potential, feasibility, and increased sensitivity for label-free and real-time biomolecular and protein detection due to its improved ability to capture analytes [13,14,15]

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Results

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