Real‐Time DNA Detection Using Reduced Graphene Oxide Field Effect Transistors

DNA Origami Nanopatterning on Chemically Modified Graphene

“…[16][17][18] GO can be thermally or chemically reduced or modified to tune the material properties, and has been successfully utilized in molecular hybrids [19,20] or composites, [21][22][23][24][25] biocompatible scaffolds or substrates, [26,27] and patterned carbon films. [28,29] In recent years, graphene-based biodevices, such as DNA carriers, [30,31] graphene nanopores for DNA sequencing, [32] and a graphene-DNA biosensor, [33,34] have been highlighted with extraordinary sensitivity, [34,35] rapid readout, [36] and good biostability. [37] These devices frequently employ singlestranded DNAs (ssDNAs) adsorbed through p-p stacking interaction between the nucleobases and the graphene surface.…”

“…[38] DNA origami structures, which consist of duplex DNA, require different surface interactions for adsorption because of the conformational screening of the nucleobases. [36,39] In addition, the substrate surface must be atomically smooth for reliable AFM imaging of the about 2 nm thick DNA origami structures. [39][40][41][42] Because of these stringent requirements, substrate materials for DNA origami studies have been restricted to mica, [39] silica, [7,40,41] and a few selfassembled monolayers (SAMs) [8,9,42] thus far.…”

Enhancing the Surface Sensitivity and Selectivity: Functionalization of Carbon Nanomaterials

“…However, graphene functionalization may require some further considerations. For instance, the use of reduced graphene oxide (rGO) involved a different chemical approach [16]. The covalent attachment of receptors to rGO was particularly challenging since the reduction process removed the main functional groups on the surface (carboxyl, epoxide…).…”

“…For instance, the XPS could be performed directly on the surface and the analysis of each functionalization steps gives some hints on the correct immobilization process with a particular benefit for covalent approaches. The carbon and nitrogen bonds could be analyzed by this technique and revealed specific spectra for the chemical functions involved [16]. Raman analysis could also be performed on the electrode surface to characterize the immobilization.…”

Graphene for DNA Biosensing

“…Chemically modified graphenes with adjustable surface chemistry have offered competitive results in biological FETs [72][73][74]. In the label-free detection, one of the pressing problems was the response to non-specific binding.…”