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Attomolar Label-Free Detection of DNA Hybridization with Electrolyte-Gated Graphene Field-Effect Transistors

2019; American Chemical Society; Volume: 4; Issue: 2 Linguagem: Inglês

10.1021/acssensors.8b00344

2379-3694

Rui Campos, Jérôme Borme, J. Rafaela L. Guerreiro, George Machado, M.F. Cerqueira, Dmitri Y. Petrovykh, Pedro Alpuim,

Molecular Junctions and Nanostructures

In this work, we develop a field-effect transistor with a two-dimensional channel made of a single graphene layer to achieve label-free detection of DNA hybridization down to attomolar concentration, while being able to discriminate a single nucleotide polymorphism (SNP). The SNP-level target specificity is achieved by immobilization of probe DNA on the graphene surface through a pyrene-derivative heterobifunctional linker. Biorecognition events result in a positive gate voltage shift of the graphene charge neutrality point. The graphene transistor biosensor displays a sensitivity of 24 mV/dec with a detection limit of 25 aM: the lowest target DNA concentration for which the sensor can discriminate between a perfect-match target sequence and SNP-containing one.