Publications

@article{He2021-uj,

title = {Volatile organic compound vapour measurements using a localised 

 surface plasmon resonance optical fibre sensor decorated with a 

 metal-organic framework},

author = {Chenyang He and Liangliang Liu and Sergiy Korposh and Ricardo Correia and Stephen P Morgan},

year  = {2021},

date = {2021-02-01},

journal = {Sensors (Basel)},

volume = {21},

number = {4},

pages = {1420},

publisher = {MDPI AG},

abstract = {A tip-based fibreoptic localised surface plasmon resonance 

 (LSPR) sensor is reported for the sensing of volatile organic 

 compounds (VOCs). The sensor is developed by coating the tip of 

 a multi-mode optical fibre with gold nanoparticles (size: 40 nm) 

 via a chemisorption process and further functionalisation with 

 the HKUST-1 metal-organic framework (MOF) via a layer-by-layer 

 process. Sensors coated with different cycles of MOFs (40, 80 

 and 120) corresponding to different crystallisation processes 

 are reported. There is no measurable response to all tested 

 volatile organic compounds (acetone, ethanol and methanol) in 

 the sensor with 40 coating cycles. However, sensors with 80 and 

 120 coating cycles show a significant redshift of resonance 

 wavelength (up to ~9 nm) to all tested volatile organic 

 compounds as a result of an increase in the local refractive 

 index induced by VOC capture into the HKUST-1 thin film. Sensors 

 gradually saturate as VOC concentration increases (up to 3.41%, 

 4.30% and 6.18% in acetone, ethanol and methanol measurement, 

 respectively) and show a fully reversible response when the 

 concentration decreases. The sensor with the thickest film 

 exhibits slightly higher sensitivity than the sensor with a 

 thinner film. The sensitivity of the 120-cycle-coated MOF sensor is 13.7 nm/% (R2 = 0.951) with a limit of detection (LoD) of 0.005% in the measurement of acetone, 15.5 nm/% (R2 = 0.996) 

 with an LoD of 0.003% in the measurement of ethanol and 6.7 nm/% (R2 = 0.998) with an LoD of 0.011% in the measurement of 

 methanol. The response and recovery times were calculated as 

 9.35 and 3.85 min for acetone; 5.35 and 2.12 min for ethanol; 

 and 2.39 and 1.44 min for methanol. The humidity and temperature 

 crosstalk of 120-cycle-coated MOF was measured as 0.5 $±$ 0.2 

 nm and 0.5 $±$ 0.1 nm in the humidity range of 50-75% 

 relative humidity (RH) and temperature range of 20-25 °C, 

 respectively.},

keywords = {localised surface plasmon resonance, metal-organic framework, optical fibre sensor, volatile organic compounds},

pubstate = {published},

tppubtype = {article}

}