Sensing Structure based on Electron Tunnelling in Plasmonic Metamaterial


An adaptable, ultra-sensitive, inexpensive sensing structure based on a novel electrically driven plasmonic metamaterial, based on the electron tunnelling effect.



There is a rising demand for gas sensors, such as oxygen gas sensors used in the medical sector, for anaesthesia machines, ventilators, and the like.

Similarly, hydrogen sensors market is likely to grow significantly over the coming years, in view of the potential role of green hydrogen for more sustainable energy systems.

Furthermore, there is a need to monitor chemical reactions, where precise stimulation and monitoring is paramount.



The proposed sensing structure has been designed to transduce a variety of chemical and physical stimuli, so that it can be used for sensing gases, as well as for real time monitoring of chemical reactions. Specifically, the sensing structure is adaptable, highly sensitive and stable. Ultra-high sensitivity to hydrogen and oxygen has been demonstrated experimentally.

Furthermore, the technology can be used to enable quantitative detection with a single molecule level sensitivity. For instance, it can work as a lab-on-a-chip device to assist in developing and understanding new chemical reactions, for which precise stimulation and monitoring are paramount.

The sensing structure can be fabricated at low costs, with a scalable fabrication process.

The proposed sensing structure is compact and can be used in miniaturized sensors. Hydrogen and Oxygen sensor prototypes had 1 cm2 in total size.



Working prototypes sensors for hydrogen and oxygen based on the developed technology are available.

The technology is protected by a pending European patent application and a pending US patent application and is available for licensing. Suitable commercial partners are sought for further development and commercialisation.

The Science

The sensing structure comprises a plurality of optical antennas. Each optical antenna is made of a plasmonic nanostructure element arranged between two electrodes to form an electron tunnelling junction. The sensing structure is configured so that the electromagnetic fields generated by adjacent optical antennas spatially overlap. Hence, adjacent optical antennas are electromagnetically coupled and act as a plasmonic metamaterial.

A target-sensitive substance is located in the electron tunnelling junction of one or more optical antennas. The target-sensitive substance can be a monolayer of polymer or molecules. In this way, the field generated by the optical antenna containing the target-sensitive substance varies in the presence of the substance itself, allowing detection.



Figure 1: A schematic view of a sensing structure according to the proposed technology



IP Status

EP 3 571 726 A1 pending European patent application 

US 16/479,511 pending US patent application

Further Information

Wang, P et al. (2018), “Reactive tunnel junctions in electrically driven plasmonic nanorod metamaterials”, Nature Nanotechnology: 13, 159–164.  doi:10.1038/s41565-017-0017-7


Patent Information:
For Information, Contact:
Lorenza Grechy
King's College London
Anatoly Zayats
Wayne Dickson
Pan Wang
Mazhar Nasir
Alexey Krasavin