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Hindi Editorial, J Nanomater Mol Nanotechnol Vol: 1 Issue: 1
Opportunity for DNA Detection using Nanoparticle-Decorated Graphene Oxide
| Ahmad I. Ayesh1* and Falah Awwad2 | |
| 1Department of Physics, United Arab Emirates University, Al Ain, United Arab Emirates | |
| 2Faculty of Information Technology, United Arab Emirates University, Al Ain, United Arab Emirates | |
| Corresponding author: Ahmad I. Ayesh, PhD Assistant Professor, Department of Physics, United Arab Emirates University, Al Ain, United Arab Emirates Tel: +971 3 7136315 E-mail: ayesh@uaeu.ac.ae |
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| Received: June 21, 2012 Accepted: June 21, 2012 Published: June 23, 2012 | |
| Citation: Ayesh AI, Awwad F (2012) Opportunity for DNA Detection using Nanoparticle-Decorated Graphene Oxide. J Nanomater Mol Nanotechnol 1:1 doi:10.4172/2324-8777.1000e101 |
Abstract
Opportunity for DNA Detection using Nanoparticle-Decorated Graphene Oxide
Graphene is a monolayer sheet of carbon atoms packed into a twodimensional (2D) honeycomb lattice. In principle, graphene has been studied for sixty years and widely used for describing properties of various carbon-based materials. However, only in 2004, graphene has been experimentally isolated and characterized in a single layer form by Novoselov et al. . Graphene has a unique electronic structure: the conical valence and conduction bands meet at a single point in the momentum space where around this point the energy varies linearly with the magnitude of the momentum. Therefore, charge carriers move through the solid with zero mass and constant velocity, i.e. its electrons move ballistically over submicron distances, even under ambient conditions. The electronic structure rapidly evolves with the number of layers, approaching the 3D limit of graphite already at 10 layers. Since graphene has unusual electronic properties, reduced dimensionality, and good stability, it has enormous potential for use in electronic field effect transistors (FETs).
| Graphene is a monolayer sheet of carbon atoms packed into a twodimensional (2D) honeycomb lattice. In principle, graphene has been studied for sixty years and widely used for describing properties of various carbon-based materials. However, only in 2004, graphene has been experimentally isolated and characterized in a single layer form by Novoselov et al. [1]. Graphene has a unique electronic structure: the conical valence and conduction bands meet at a single point in the momentum space where around this point the energy varies linearly with the magnitude of the momentum. Therefore, charge carriers move through the solid with zero mass and constant velocity, i.e. its electrons move ballistically over submicron distances, even under ambient conditions. The electronic structure rapidly evolves with the number of layers, approaching the 3D limit of graphite already at 10 layers. Since graphene has unusual electronic properties, reduced dimensionality, and good stability, it has enormous potential for use in electronic field effect transistors (FETs). Additionally, graphene is biocompatible and exhibits good chemical stability; therefore, it represents a suitable system to be used for biological and florescent sensors, drug delivery, and living cell studies. Nevertheless, mass production of graphene with reliable procedure, cost, and reliable integration within FET devices are not realized yet. | |
| Graphene oxide (GO) was found as a promising alternative to graphene [2]. GO is a water soluble colloidal suspension from the chemical exfoliation of graphite and can be reduced thermally or chemically to conductive GO. In fact, GO has been used as a cheap alternative to graphene in a variety of conductometric biosensors [3] that utilize FET structure. Thin films of GO (FET channel) can be prepared on SiO2/doped-Si substrates by various self-assembly methods including: spin coating, vacuum filtration, spray deposition, liquid/air interface, and Langmuir-Blodgett. The film is then reduced with thermal annealing to obtain a conductive film of GO. The cost of preparing those films is cheap compared with the pricy graphene films, yet, they have a comparable sensitivity to that of graphene [4]. Source and drain electrodes can be fabricated by standard lithography technique. The doped Si substrate can be used as a FET back gate. | |
| Reduced graphene oxide was found to adsorb single-standard DNA (ssDNA) through the p-p electron interaction between the carbon ring of graphene and the ring structure of in nucleic acid [5]. The p-p interaction and discrimination occurs simultaneously at all four DNA bases at different oxidation potentials. The sensitivity of GO sensors can be tuned by decorating the GO films with suitable metallic nanoparticles. Recent studies [6] reported enhancement in the sensitivity for ssDNA when decorating GO with platinum or gold nanoparticles because of the metal-S bonding. Herein, ssDNA is adsorbed at the metal nanoparticles (instead of the adsorption at the unspecified surface of the GO), thus, a corresponding change in the source-drain current (Isd) of the FET is observed. | |
| GO represents an effective system for the development of graphene based biosensors. Nevertheless, intensive research efforts are needed to address two main fields: the first one is the fabrication method of the GO thin film in order to produce a single layer of GO. The second field is related to the type and characteristics of the nanoparticles used to adjust the sensitivity of the sensor. Here we list few examples of research areas that might be interesting: i) testing new types of metallic nanoparticles such as silver, ii) the size of the nanoparticles, iii) the nanoparticle capping agent, and iv) the nanoparticle coverage on the GO thin film. | |
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