Biosensors (Aug 2021)

Sequence-Independent DNA Adsorption on Few-Layered Oxygen-Functionalized Graphene Electrodes: An Electrochemical Study for Biosensing Application

  • Narges Asefifeyzabadi,
  • Torrey E. Holland,
  • Poopalasingam Sivakumar,
  • Saikat Talapatra,
  • Ishani M. Senanayake,
  • Boyd M. Goodson,
  • Mohtashim H. Shamsi

DOI
https://doi.org/10.3390/bios11080273
Journal volume & issue
Vol. 11, no. 8
p. 273

Abstract

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DNA is strongly adsorbed on oxidized graphene surfaces in the presence of divalent cations. Here, we studied the effect of DNA adsorption on electrochemical charge transfer at few-layered, oxygen-functionalized graphene (GOx) electrodes. DNA adsorption on the inkjet-printed GOx electrodes caused amplified current response from ferro/ferricyanide redox probe at concentration range 1 aM–10 nM in differential pulse voltammetry. We studied a number of variables that may affect the current response of the interface: sequence type, conformation, concentration, length, and ionic strength. Later, we showed a proof-of-concept DNA biosensing application, which is free from chemical immobilization of the probe and sensitive at attomolar concentration regime. We propose that GOx electrodes promise a low-cost solution to fabricate a highly sensitive platform for label-free and chemisorption-free DNA biosensing.

Keywords