scholarly journals Metal-organic framework thin films on a surface of optical fibre long period grating for chemical sensing

2017 ◽  
Author(s):  
J. Hromadka ◽  
B. Tokay ◽  
S. James ◽  
S. Korposh
2015 ◽  
Vol 221 ◽  
pp. 891-899 ◽  
Author(s):  
Jiri Hromadka ◽  
Begum Tokay ◽  
Stephen James ◽  
Ralph P. Tatam ◽  
Sergiy Korposh

2021 ◽  
Author(s):  
James Ellis ◽  
Scott Crawford ◽  
Ki-Joong Kim

Metal-organic frameworks (MOFs) have been widely investigated as chemical sensing materials due to their periodic porosity, tunable chemical functionalities such as Lewis acid/base sites, potential conductivity and/or sensitive optical properties....


Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1420
Author(s):  
Chenyang He ◽  
Liangliang Liu ◽  
Sergiy Korposh ◽  
Ricardo Correia ◽  
Stephen P. Morgan

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.


2020 ◽  
Vol 32 (5) ◽  
pp. 1784-1793 ◽  
Author(s):  
Timothée Stassin ◽  
Ivo Stassen ◽  
João Marreiros ◽  
Alexander John Cruz ◽  
Rhea Verbeke ◽  
...  

Langmuir ◽  
2013 ◽  
Vol 29 (27) ◽  
pp. 8657-8664 ◽  
Author(s):  
Wei-Jin Li ◽  
Shui-Ying Gao ◽  
Tian-Fu Liu ◽  
Li-Wei Han ◽  
Zu-Jin Lin ◽  
...  

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