| Title: | Graphene oxide integrated silicon photonics for detection of vapour phase volatile organic compounds |
| Author(s): | Leo Tsui HC; Alsalman O; Mao B; Alodhayb A; Albrithen H; Knights AP; Halsall MP; Crowe IF; |
| Address: | "Photon Science Institute and Department of Electrical and Electronic Engineering, The University of Manchester, Manchester, United Kingdom, M13 9PL. National Graphene Institute and Department of Physics and Astronomy, The University of Manchester, Manchester, United Kingdom, M13 9PL. Aramco Laboratory for Applied Sensing Research, King Abdullah Institute for Nanotechnology, King Saud University, Riyadh, 11451, Saudi Arabia. Department of Engineering Physics and Centre for Emerging Device Technology, McMaster University, Hamilton, L8S 4L7, Ontario, Canada. Photon Science Institute and Department of Electrical and Electronic Engineering, The University of Manchester, Manchester, United Kingdom, M13 9PL. iain.crowe@manchester.ac.uk" |
| DOI: | 10.1038/s41598-020-66389-9 |
| ISSN/ISBN: | 2045-2322 (Electronic) 2045-2322 (Linking) |
| Abstract: | "The optical response of a graphene oxide integrated silicon micro-ring resonator (GOMRR) to a range of vapour phase Volatile Organic Compounds (VOCs) is reported. The response of the GOMRR to all but one (hexane) of the VOCs tested is significantly higher than that of the uncoated (control) silicon MRR, for the same vapour flow rate. An iterative Finite Difference Eigenmode (FDE) simulation reveals that the sensitivity of the GO integrated device (in terms of RIU/nm) is enhanced by a factor of ~2, which is coupled with a lower limit of detection. Critically, the simulations reveal that the strength of the optical response is determined by molecular specific changes in the local refractive index probed by the evanescent field of the guided optical mode in the device. Analytical modelling of the experimental data, based on Hill-Langmuir adsorption characteristics, suggests that these changes in the local refractive index are determined by the degree of molecular cooperativity, which is enhanced for molecules with a polarity that is high, relative to their kinetic diameter. We believe this reflects a molecular dependent capillary condensation within the graphene oxide interlayers, which, when combined with highly sensitive optical detection, provides a potential route for discriminating between different vapour phase VOCs" |
| Notes: | "PubMed-not-MEDLINELeo Tsui, H C Alsalman, Osamah Mao, Boyang Alodhayb, Abdullah Albrithen, Hamad Knights, Andrew P Halsall, Matthew P Crowe, Iain F eng England 2020/06/14 Sci Rep. 2020 Jun 12; 10(1):9592. doi: 10.1038/s41598-020-66389-9" |
