Epitaxial graphene immunosensor for human chorionic gonadotropin

Sofia Teixeira, G. Burwell, A. Castaing, D. Gonzalez, R. S. Conlan, O. J. Guy

Research output: Contribution to journalArticle

51 Scopus citations

Abstract

Human chorionic gonadotropin (hCG), a 37 kDa glycoprotein hormone, is a key diagnostic marker of pregnancy and has been cited as an important biomarker in relation to cancerous tumors found in the prostate, ovaries and bladder. A novel chemically-modified epitaxial graphene diagnostic sensor has been developed for ultrasensitive detection of the biomarker hCG. Multi-layer epitaxial graphene (MEG), grown on silicon carbide substrates, was patterned using electron beam lithography to produce channel based devices. The MEG channels have been amine terminated using 3-Aminopropyl-triethoxysilane (APTES) in order to attach the anti-hCG antibody to the channel. Detection of binding of hCG with its graphene-bound antibody was monitored by measuring reduction of the channel current of the graphene biosensor. The sensitivity of the sensor device was investigated using varying concentrations of hCG, with changes in the channel resistance of the sensor observed upon exposure to hCG. The detection limit of the sensor was 0.62 ng/mL and the sensor showed a linear response to hCG in the range 0.62-5.62 ng/mL with a response of 142 Ω/ng/mL. At concentrations above 5.62 ng/mL the sensor begins to saturate.

Original languageEnglish (US)
Pages (from-to)723-729
Number of pages7
JournalSensors and Actuators, B: Chemical
Volume190
DOIs
StatePublished - 2014

Keywords

  • Amperometric
  • APTES
  • Epitaxial grapheme
  • Human chorionic gonadotropin
  • Immunosensor
  • SiC

ASJC Scopus subject areas

  • Instrumentation
  • Materials Chemistry
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

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