Abstract
Fast and reliable DNA sequencing is a long-standing target in biomedical research. Recent advances in graphene-based electrical sensors have demonstrated their unprecedented sensitivity to adsorbed molecules, which holds great promise for label-free DNA sequencing technology. To date, the proposed sequencing approaches rely on the ability of graphene electric devices to probe molecular-specific interactions with a graphene surface. Here we experimentally demonstrate the use of graphene field-effect transistors (GFETs) as probes of the presence of a layer of individual DNA nucleobases adsorbed on the graphene surface. We show that GFETs are able to measure distinct coverage-dependent conductance signatures upon adsorption of the four different DNA nucleobases; a result that can be attributed to the formation of an interface dipole field. Comparison between experimental GFET results and synchrotron-based material analysis allowed prediction of the ultimate device sensitivity, and assessment of the feasibility of single nucleobase sensing with graphene.
Highlights
Fast and reliable DNA sequencing is a long-standing target in biomedical research
We demonstrate that graphene field-effect transistors (GFETs) are capable of detecting distinct coveragedependent conductance signatures upon adsorption of the four different DNA nucleobases: adenine, guanine, cytosine and thymine
Using simultaneous synchrotron-based X-ray photoelectron spectroscopy (XPS) measurements we explore the molecule-specific limit of adsorbed dipole-induced doping in a range of graphene materials
Summary
Fast and reliable DNA sequencing is a long-standing target in biomedical research. Recent advances in graphene-based electrical sensors have demonstrated their unprecedented sensitivity to adsorbed molecules, which holds great promise for label-free DNA sequencing technology. Electrical sequencing using graphene and nanopore technologies has recently attracted great attention due to the possibility to provide real-time sequencing of a whole single DNA molecule[3,4,5,6,7,8,9,10,11] These methods are based on the use of graphene as an electrical readout-based chemical sensor while a strand of DNA is fed through a nanopore[2,3,4,10]. Most of the graphene-based sequencing technologies are fundamentally reliant on detecting molecular-specific interactions of individual nucleobases with a graphene surface[4] or its defects[5] These interactions need to induce electronic modifications that are detectable by graphene electrical devices. We analyse the sensitivity of our GFET devices and provide an estimate for the resolution limit in realistic scaled-down devices
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