Gas identification with graphene plasmons

• Published in: Nature communications Vol. 10; no. 1; pp. 1131 - 7
• Main Authors: Hu, Hai, Yang, Xiaoxia, Guo, Xiangdong, Khaliji, Kaveh, Biswas, Sudipta Romen, García de Abajo, F. Javier, Low, Tony, Sun, Zhipei, Dai, Qing
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 08-03-2019; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/357/918; 639/624/400/1021; 639/925/927/356; Chemical reactions; Graphene; Health care; Humanities and Social Sciences; Identification; Monitoring; multidisciplinary; Nitrogen dioxide; Nitrous oxide; Organic chemistry; Organic compounds; Plasmons; Refractivity; Response time; Science; Science (multidisciplinary); Security; Sulfur dioxide; VOCs; Volatile organic compounds
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-09008-0

Identification of gas molecules plays a key role a wide range of applications extending from healthcare to security. However, the most widely used gas nano-sensors are based on electrical approaches or refractive index sensing, which typically are unable to identify molecular species. Here, we report label-free identification of gas molecules SO
2
, NO
2
, N
2
O, and NO by detecting their rotational-vibrational modes using graphene plasmon. The detected signal corresponds to a gas molecule layer adsorbed on the graphene surface with a concentration of 800 zeptomole per μm
2
, which is made possible by the strong field confinement of graphene plasmons and high physisorption of gas molecules on the graphene nanoribbons. We further demonstrate a fast response time (<1 min) of our devices, which enables real-time monitoring of gaseous chemical reactions. The demonstration and understanding of gas molecule identification using graphene plasmonic nanostructures open the door to various emerging applications, including in-breath diagnostics and monitoring of volatile organic compounds.
Identification of gas molecules is crucial in healthcare and security applications. Here the authors achieve label-free identification of SO
2
, NO
2
, N
2
O, and NO gas molecules by detecting their rotational-vibrational modes using graphene nanoribbon plasmons.