Creation of Reduced Graphene Oxide Based Field Effect Transistors and Their Utilization in the Detection and Discrimination of Nucleoside Triphosphates

Abstract

Two low-cost, micropatterned, solution-gated field effect transistors (modified FET and unmodified FET) based on reduced graphene oxide (RGO) were developed and used for detection and discrimination of nucleoside triphosphates (NTPs). The modified FET was realized by simple deposition of a positively charged bis-pyrenyl derivative, py-diIM-py, onto the conducting RGO strips of the unmodified FET. The electrical properties and sensing behaviors of the as-prepared devices were studied comprehensively. Electrical transfer property tests revealed that both of the two FETs exhibit V-shaped ambipolar field effect behavior from p-type region to n-type region. Sensing performance studies demonstrated that modification of the native FET with py-diIM-py improves its sensing ability to NTPs-GTP and ATP in particular. The detection limit of GTP and ATP was as low as 400 nM, which is the lowest value for graphene-based electronic sensors reported so far. Furthermore, based on the cross-reactive responses of the two devices to NTPs, NTPs can be conveniently distinguished via combining use of the two devices. The enhancement of the modifier (py-diIM-py) to the sensing performance of the FET is tentatively attributed to its possible mediation role in sticking onto RGO strips and accumulating analytes by electrostatic association with the relevant species. Because they are sensitive and fast in response, simple and low-cost in preparation, and possibly useful in sensor-array fabrication, the developed sensors show great potential in real-life application.

Graphene Oxide and Derivatives: The Place in Graphene Family

“…Usually it consists of the film and a couple of metallic contacts. In order to enhance sensitivity more complicated FET structure can be constructed [121]. For selective sensitivity the surface can be modified by catalyst particles or chemical agents to enhance charge transfer from detecting agent to GO layer.…”

Graphene field-effect transistors as bioanalytical sensors: design, operation and performance

“…Reference electrodes made of Ag/AgCl represent a common choice since their use in electrolyte buffer is well calibrated. 103 Others have reported immersed gate electrodes made of silver 43,104,105 or platinum 106 wires. Coplanar gate electrodes are patterned on the substrate in a similar approach as for source and drain electrodes, using deposition of metals such as platinum, 55 silver 107 or gold.…”

Physical properties and device applications of graphene oxide

“…Chang et al [258] also demonstrated that the large-area few-layer RGO films exhibit ambipolar charge transport characteristics in a bottom-gate FET architecture, which can be used as a phototransistor. Yu et al [259] showed that both the as-prepared RGO FET and FET with RGO modified by a bis-pyrenyl derivative, py-diIM-py, exhibit V-shaped ambipolar field effect behavior from p-type region to ntype region.…”

“…The detection limit of this RGO-based FET biosensor is around 0.2 ng/mL, which is among the best of reported carbon nanomaterial based protein sensors and can be further optimized by tuning the sensor structure. Besides, GO-based FETs with high sensitivity to other biomaterials were also reported, including the glucose with a limit of detection of 1 nM and a rapid response within 1 s [263], GTP and ATP with a detection limit as low as 400 nM [259], and matrilysin (MMP-7) with a limit of detection of 10 ng/mL (400 pM) [300]. sensitivity can be ascribed mainly to the electron transfer between the reduced GO and the adsorbed gaseous molecules of NO2 or NH3.…”