Publications

@article{Liu2022-bm,

title = {Localised plasmonic hybridisation mode optical fibre sensing of 

 relative humidity},

author = {Liangliang Liu and Serhiy Korposh and David Gomez and Ricardo Correia and Barrie R Hayes-Gill and Stephen P Morgan},

year  = {2022},

date = {2022-02-01},

journal = {Sens. Actuators B Chem.},

volume = {353},

number = {131157},

pages = {131157},

publisher = {Elsevier BV},

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.},

keywords = {Humidity sensor, LSPR, optical fibre sensor, Plasmonic   hybridisation},

pubstate = {published},

tppubtype = {article}

}