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Highly Sensitive Gas Sensor Using Plasmonic Antennas

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Researchers
Bhaven Mehta
Mona Zaghloul
Managed By
Jerry Comanescu
Licensing Associate jcomanescu@gwu.edu (202) 994-8975
Patent Protection

Provisional Patent Application Filed

Gas sensors are necessary for diverse purposes such as industrial manufacturing, environmental monitoring and airport/port security.  The main challenge for current sensors is the trade-off between sensitivity and selectivity. When current sensors are functionalized for selectivity to detect specific molecules, their sensitivity decrease drastically. Current technologies are also costly and lack portability due to elements such as chip heaters and UV sources.

Researchers at the GW university have developed novel technologies that overcome all these problems, including the aforementioned trade-off. They have devised new chemical sensors which are both highly sensitive and selective. These novel technologies can detect very low concentrations of distinct molecules in the air (e.g. <2 ppb for ethanol). The most recent ultra-sensitive chemical gas sensors developed by our researchers are made based on ONAs (Optical Nano Antennas) covered with graphene oxide and/or graphene.  

Novel graphene-loaded dipole nano antennas allow us assessing changes in the resonance wavelength. These metal nano-particle antennas enable highly sensitive detection. In addition, the use of graphene oxide and graphene enables more versatile gas sensors. Selectivity is introduced by functionalizing the graphene and graphene oxide, for example by replacing its –OH (hydroxyl) and –COOH (carboxyl) groups with hydrazine to detect explosive gases such as DMP, DNT, or hydrogen cyanide.  This leads to gas sensors that have superior sensitivity, selectivity, and portability compared to existing sensors. These innovative sensors are also more cost-effective to manufacture.

GW researchers have produced these sensors, which have been successfully tested with gases such as acetone and water vapor, after the initial simulations also demonstrated the efficacy of the proof-of-concept.  Both graphene covered ONAs and graphene oxide covered ONAs have also been tested for ethanol, nitrogen, and toluene. Further testing for other explosive gases will be conducted in collaboration with Naval Research Laboratory.

Applications:

·  Industrial monitoring for process control

·  Security in airports and ports; detectors of explosive gases and other chemical warfare agents

·  Environmental monitoring

·  Food quality control, healthcare and other biological sensing

Advantages:

·  Higher sensitivity and selectivity than current technologies

·  Higher portability and lower power demand

·  Lower cost of manufacturing than current sensors


Plasmonic Sensor Structure