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

Abstract

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.

Ultrasensitive detection of nucleic acids using deformed graphene channel field effect biosensors

“…Especially, large area graphene, which is grown through chemical vapor deposition (CVD) method, has been utilized in electrical systems, such as FET device for bio-sensing 5 including detection of pH 11 , microorganisms 12 , blood sugar 12 , and more specifically, proteins at concentrations of 10 fM 12,13 , and nucleic acids (DNA or RNA) at the 100 fM concentrations 5,14 . There are a few reports that showed DNA and RNA detection at aM level, however, had significant level of background noise and lacked robust controls 15,16 . Further sensitivity would be highly desirable for detection of very rare molecules, such as micro RNA (miRNA) or cell-free DNA (cfDNA), from unamplified samples 17 .…”

Recent developments in carbon-based two-dimensional materials: synthesis and modification aspects for electrochemical sensors

“…One has to be cautious as there is no bandgap control upon non-covalent functionalization, which might be used in maximizing the detection sensitivity by minimizing the electrical noise [76]. Pyrene derivatives have been reported as non-covalent linker between graphene and other (bio-)molecules, which act either as probe or as target [32,82,83]. The π-interaction of graphene with carbon nanotubes enables the processability of the former hydrophobic carbon wires in aqueous solution [84].…”

Switchable conformational changes of DNA nanogel shells containing disulfide–DNA hybrids for controlled drug release and efficient anticancer action

“…A more precise characterization of the dsDNA hybrids arrangement in the investigated NGs was possible with the electrochemical impedance spectroscopy (EIS), which is widely applied for detection of various DNA forms and tracking of the hybridization process. 29,36 The EIS parameters were determined for layers of DNA attached directly to the electrode surface. 37,38 In the tting process the equivalent EIS electrical circuit developed by Randles was used, 39 see inset in Fig.…”