Abstract
We report on chemical vapour deposition (CVD) graphene field effect transistor (GFET)
immunosensors for the sensitive detection of Human Chorionic Gonadotropin (hCG), a glycoprotein
risk biomarker of pancreatic, prostate, lung and stomach cancers [1-4]. The GFET sensors were
fabricated on Si/SiO2 substrate using photolithography with evaporated chromium and sputtered gold
contacts. GFET channels were functionalized with a linker molecule, 1-Pyrenebutyric acid Nhydroxysuccinimide (Pyr-NHS) ester, to immobile anti-hCG antibody (Ab) on the surface of graphene.
The Pyr-NHS has an aromatic pyrenyl group, which can strongly interact with the graphene surface,
via a non-covalent π-π bonding to retain sp2
lattice. Binding reaction of the antibody with varying
concentration levels of hCG antigen demonstrated the limit of detection of the GFET sensors to be
better than 1 pg/mL [1] using four-probe electrical measurements [5-6]. We also demonstrate that
annealing can significantly improve the carrier transport properties of GFETs and shift the Dirac point
with reduced p-doping in back-gated measurements. The developed GFET biosensors are generic,
selective, fast, low-cost and could find applications in a broad range of point-of-care medical
diagnostics in addition to cancer, such as neurodegenerative (Alzheimer’s, Parkinson’s) and
cardiovascular disorders. We acknowledge funding from UK’s EPSRC, contract number
EP/M006301/1, and the University of Plymouth, GD105227.
Original language | English |
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Publication status | Published - 10 Sept 2018 |
Event | Graphene Week 2018 - Graphene Week 2018 Duration: 10 Sept 2018 → … |
Conference
Conference | Graphene Week 2018 |
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Period | 10/09/18 → … |