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Article Dans Une Revue Advanced Healthcare Materials Année : 2020

DNA Hybridization Measured with Graphene Transistor Arrays

Résumé

Arrays of field-effect transistors are fabricated from chemical vapor deposition grown graphene (GFETs) and label-free detection of DNA hybridization performed down to femtomolar concentrations. A process is developed for large-area graphene sheets, which includes a thin Al 2 O 3 layer, protecting the graphene from contamination during photolithographic patterning and a SiO x capping for biocompatibility. It enables fabrication of high-quality transistor arrays, exhibiting stable close-to-zero Dirac point voltages under ambient conditions. Passivation of the as-fabricated chip with a layer composed of two different oxides avoids direct electrochemical contact between the DNA solutions and the graphene layer during hybridization detection. DNA probe molecules are electrostatically immobilized via poly-l-lysine coating of the chip surface. Adsorption of this positively charged polymer induces a positive shift of the Dirac point and subsequent immobilization of negatively charged DNA probes induces a negative shift. Spatially resolved hybridization of DNA sequences is performed on the GFET arrays. End-point as well as real-time in situ measurements of hybridization are achieved. A detection limit of 10 fm is observed for hybridization of 20-nucleotide DNA targets. Typical voltage signals are around 100 mV and spurious drifts below 1 mV per hour.
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Origine : Publication financée par une institution

Dates et versions

hal-02989040 , version 1 (12-11-2020)

Identifiants

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Kokoura Mensah, Ismaïl Cissé, Aurélie Pierret, Michael Rosticher, José Palomo, et al.. DNA Hybridization Measured with Graphene Transistor Arrays. Advanced Healthcare Materials, 2020, 9 (16), pp.2000260. ⟨10.1002/adhm.202000260⟩. ⟨hal-02989040⟩
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