Localised plasmonic hybridisation mode optical fibre sensing of relative humidity

Liu, Liang Liang; Korposh, Serhiy; Gomez, David; Correia, Ricardo; Hayes-Gill, Barrie R.; Morgan, Stephen P.

Abstract

This work reports an optical fibre probe functionalised with ‘cotton-shaped’ gold-silica nanostructures for relative humidity (RH) monitoring. The sensor response utilises the localised surface plasmon resonance (LSPR) of self-assembled nanostructures: gold nanospheres (40 nm) surrounded by one layer of poly (allylamine hydrochloride) and hydrophilic silica nanoparticles (10–20 nm) on the end-facet of an optical fibre via a wavelength shift of the reflected light. Sensor optimisation is investigated by varying the density of gold nanoparticles on the end-facet of an optical fibre. It is demonstrated that the plasmonic hybridisation mode appearing when the average gold interparticle distance is small (Median: 7.5 nm) is more sensitive to RH after functionalisation than the singular plasmonic mode. The plasmonic hybridisation mode sensor demonstrates a high linear regression to RH with a sensitivity of 0.63 nm/%RH and excellent reversibility. The response time (T10–90%) and recovery time (T90–10%) are calculated as 1.2 ± 0.4 s and 0.95 ± 0.18 s. The sensor shows no measurable cross-talk to temperature in the tested range between 25 °C to 40 °C and the 95% limit of agreement is 3.1%RH when compared to a commercial reference sensor. Simulation with finite element analysis reveals a polarisation-dependent plasmonic hybridisation with a redshift of plasmonic wavelength as a decrease of the interparticle distance and a higher refractive index sensitivity, which results in a high sensitivity to RH as observed in the experiment.

Citation

Liu, L. L., Korposh, S., Gomez, D., Correia, R., Hayes-Gill, B. R., & Morgan, S. P. (2022). Localised plasmonic hybridisation mode optical fibre sensing of relative humidity. Sensors and Actuators B: Chemical, 353, Article 131157. https://doi.org/10.1016/j.snb.2021.131157

• Journal Article Type: Article
• Acceptance Date: Nov 23, 2021
• Online Publication Date: Nov 27, 2021
• Publication Date: Feb 15, 2022
• Deposit Date: Dec 3, 2021
• Publicly Available Date: Nov 28, 2022
• Journal: Sensors and Actuators B: Chemical
• Print ISSN: 0925-4005
• Publisher: Elsevier BV
• Peer Reviewed: Peer Reviewed
• Volume: 353
• Article Number: 131157
• DOI: https://doi.org/10.1016/j.snb.2021.131157
• Keywords: Materials Chemistry; Electrical and Electronic Engineering; Metals and Alloys; Surfaces, Coatings and Films; Condensed Matter Physics; Instrumentation; Electronic, Optical and Magnetic Materials
• Public URL: https://nottingham-repository.worktribe.com/output/6849187
• Publisher URL: https://www.sciencedirect.com/science/article/abs/pii/S0925400521017251?via%3Dihub