Detection of Biomolecules in High Ionic Strength physiological Solution Using Electrochemically Reduced Graphene oxide Field-Effect Transistor Immunosensor

EasyChair Preprint no. 4622

Abstract

Graphene has capability for electrical biosensing due to its two-dimensional nature and high carrier mobility. In electrochemically reduced graphene oxide (ERGO) based field-effect transistor (FET), conductivity has been change to a great extent. Low noise FET biosensors have been fabricate with electrochemically reduced graphene oxide(ERGO) on fluorine doped tin oxide(FTO) glass, directly by electrochemical reduction of GO in solution. It has been observed that the sensor is capable of detecting down to1 fM concentration of Hepatitis-B in serum.  Detecting charges and the sensitivity of the devices in high ionic strength solutions suffers from the ionic screening due to mobile ions present in the solution and detection of target molecules is a challenge due to the inherent problem of ionic screening in small Debye length. Here we successfully demonstrate that the fundamental ionic screening effect can be mitigated by using smooth ERGO-FET as a high-frequency biosensor. The charge transfer probability between the biomolecules and the surface even at high ionic strength of the buffer have been raises and these features coupled with high frequency sensing have enabled detection down to 1 fM Hep-B in a high ionic strength buffer (150mM) at 8 MHz.

Keyphrases: Debye length, high frequency, ionic screening

@Booklet{EasyChair:4622,
  author = {Joyeeta Basu Pal},
  title = {Detection of Biomolecules in High Ionic Strength physiological Solution Using Electrochemically Reduced Graphene oxide Field-Effect Transistor Immunosensor},
  howpublished = {EasyChair Preprint no. 4622},

  year = {EasyChair, 2020}}