Graphene Oxide - Paving the Way for Chemical Sensors and Electronics

Graphene is a two-dimensional building block which can be heaped as three-dimensional graphite and rolled into single layer graphene oxide nanotubes. The invention of this wonder material has stirred the world of material science and caught the attention of researchers globally. Graphene oxide Nano composites, the newest addition to this marvel, have paved the way for chemical sensing which can be used for monitoring inflammability, toxicity, and explosive nature of elements.

Many types of research are being conducted worldwide on chemical sensing technology and their application in the fields of environmental pollution, the spread of life-threatening diseases, and terrorism. Chemical sensors enable the detection of small amounts of chemicals and gases and this is one of the latesttechnologies being used in different sectors to monitor and regulate the quality of air in and around human habitation. Such sensors have potential application in the energy, space and nuclear sectors. However, the functioning and efficiency of the sensors depend entirely on the sensing material used.

Graphene has excellent chemical, structural, electronic, and electrical properties that make it an outstanding choice for chemical sensors. Graphene and graphene oxide based hybrid composites are an exceptional material for the fabrication of chemical sensors for versatile sensing applications. Binary oxides such as TiO2, ZnO, SnO2, CuO and WO3 combine with graphene as Nano composites and display excellent properties in terms of sensing amounts of hazardous chemicals and gas. Acid free GO is used to form Nano composites and synthesis of graphene in an acid free environment bypasses the use of various toxic chemicals and acids that are normally used in the preparation of graphene-based Nano composites.

Apart from chemical sensors and biosensors, another field that has been taken aback by the invention of graphene is electronics. Almost every modern electronic, used in households, run on Optoelectronics that makes use of a Transparent Conductive Film in its components. Touchscreens, LEDs, organic light-emitting diodes and organic photovoltaic cells - all consist of a Transparent Conductive Film. Due to its excellent electrical conductivity, mechanical properties, optical transparency, and cost-effectiveness, a graphene oxide film has been considered ideal for replacing the currently being used and expensive indium tin oxide as TCFs.

Various Applications of Graphene Oxide in Different Fields

Did you know that whenever you used your pencil to draw a line, you made Graphene? Yes, that’s true! In fact, graphene is renowned as the world’s thinnest material and has revolutionized various aspects of our daily lives. The existence of Graphene was known, but the process of extracting it from Graphite was undetermined until two researchers, Andre and Kostya isolated it and studied its extraction and application as Graphene Oxide.

GO or the oxide of Graphene is a distinct material that can be considered as a single molecular structure of graphite with different oxygen containing functionalities. The most commonly used modern procedures for the synthesis of GO is based on the method in which graphite is oxidized by a solution of potassium permanganate in sulfuric acid. GO can further be reduced to rGO or reduced GO that can again be formed into a thin film from an aqueous dispersion of GO in water. This reduced Graphene Oxide film has moderate conductivity and has found application in various electronic devices.

Apart from being used in electronic devices, GO and reduced GO have found application in Nano composite materials, energy storage, polymer composite materials, catalysis, biomedical applications, and also as surfactants. Here are some popular applications of this chemical marvel:

Electronics - Many electronic devices such as the graphene based field effect transistor or GFET have been fabricated using GO as a starting material for at least one of the components. FETs that use graphene have been used as both chemical sensors and biosensors. As biosensors, find application in detection of DNA and have been used as an electrochemical glucose sensor.

Energy Storage - Among the different fields of materials science that were affected by the extended study on Graphene was the world of electrochemical energy-storage devices.  Graphene finds application both as an active component and as an inactive material. Nano composites of Reduced Graphene Oxide have been used in lithium ion batteries and electrochemical capacitors for high capacity energy storage. 

Biomedical Applications - One major application of GO in the biomedical branch is its use as a constituent in drug delivery systems. Another research looked at using reduced Graphene Oxide powder for the electrochemical sensing of nitrite content in exhaled breath condensate.