Investigation of electrolysis-related modification of graphene films in biosensors

I A Eliseyev,E V Gushchina,M V Puzyk,A D Roenkov,E I Shabunina,N M Shmidt,A S Usikov,S P Lebedev,A A Voronina,Yu M Makarov,G A Oganesyan

doi:10.1088/1742-6596/2103/1/012103

Abstract

In this work, the modification of the surface parameters of graphene chips after electrolysis treatment in a NaClO4 aqueous solution has been studied. Two electrolysis modes have been analysed. In the first one, a negative potential (-0.2 V) is applied to the graphene chips, while in the second one the potential is positive (0.8 V). Investigation using a number of techniques including atomic force microscopy, Kelvin probe force microscopy, Raman spectroscopy, measurements of current-voltage characteristics and low-frequency noise has shown that the electrolysis mode with application of a positive potential on graphene chips decreases the 1/f noise and allows one to obtain a uniform surface potential distribution while leaving the graphene structure undamaged. The results of this study help to understand the efficiency and reproducibility of the procedure for electrolysis treatment of graphene chips.

Highlights

Graphene is a promising material for creating biosensors capable of diagnosing extremely low concentrations of biomolecules associated with various socially significant diseases at their early stages, including HIV, hepatitis, cancer, influenza, and COVID-19
It can be seen that electrolysis treatment in mode I leads to an increase in Sv relative to the initial values by 5 times
It was shown that the mode of electrolysis with a negative potential applied on graphene results in formation of defects and increased inhomogeneity of the surface potential of graphene

Summary

Introduction

Graphene is a promising material for creating biosensors capable of diagnosing extremely low concentrations of biomolecules associated with various socially significant diseases at their early stages, including HIV, hepatitis, cancer, influenza, and COVID-19. Experiments recently carried out at the Smorodintsev Institute of Influenza have shown that the biosensors based on graphene films grown at the Ioffe Institute allow the detection of orders of magnitude lower concentrations of influenza viruses in comparison with traditional methods of enzyme immunosorbent assay [2]. Selective sensitivity of graphene films is achieved by special processing creating additional covalent bonds that provide chemical reactions with detected biomolecules. The fabrication of graphene-based biosensors usually includes a number of preparatory stages: surface potential modification, functionalization (attachment of the phenylamine group), and immobilization (attachment of antibodies related to antigens). It is necessary to ensure a uniform distribution of the surface potential across the sample, which enables one to achieve

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Conclusion