Three-dimensional graphene-polydimethylsiloxane composite as a conductive substrate for cell-based electrochemical detection

Recently, three-dimensional (3D) graphene interconnected network has attracted a great interest in biological applications due to its biocompatibility, high electrical conductivity, large surface area and porous structure that is appropriate for cell growth. In this work, we cultured L929 fibroblast cells on 3D graphene composited with polydimethylsiloxane (PDMS) which is also used as working electrode for assessment of the electrochemical cell signal. Graphene was grown on Ni foams by chemical vapor deposition method using acetylene/hydrogen. The characterizations by scanning electron microscope (SEM) showed that open-pores of graphene foam were partially covered with thin layers of PDMS. In addition, PDMS-3D graphene composite exhibited a good electrical conductivity of 0.03 Scm-1. Cells were immobilized on PDMS-3D graphene composite surface and the electrochemical behavior of cell was determined by cyclic voltammetry (CV). The result showed oxidation peak current at +0.8 V whose amplitude was linearly proportional to cell number. Alamar blue assay was performed to confirm the results of cell viability data obtained from CV analysis. The result from immunofluorescence staining of vinculin affirmed that cell adhered on surface of PDMS-3D graphene composite. Therefore, 3D-graphene is highly biocompatible and can potentially be used as conductive substrate for cell culture in cell-based electrochemical applications such as drug or toxin screening.