Browsing by Author "Morgan, S. P."
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Item Open Access Highly sensitive contact pressure measurements using FBG patch in endotracheal tube cuff(SPIE, 2016-05-31) Correia, Ricardo N.; Blackman, O. R.; Hernandez, F. U.; Korposh, Sergiy; Morgan, S. P.; Hayes-Gill, R.; James, Stephen W.; Evans, D.; Norris, A.A method for measuring the contact pressure between an endotracheal tube cuff and the trachea was designed and developed by using a fibre Bragg grating (FBG) based optical fibre sensor. The FBG sensor is encased in an epoxy based UV-cured cuboid patch and transduces the transversely loaded pressure into an axial strain that induces wavelength shift of the Bragg reflection. The polymer patch was created by using a PTFE based mould and increases tensile strength and sensitivity of the bare fibre FBG to pressure to 2.10×10-2 nm/kPa. The characteristics of the FBG patch allow for continuous measurement of contact pressure. The measurement of contact pressure was demonstrated by the use of a 3D printed model of a human trachea. The influence of temperature on the measurements is reduced significantly by the use of a second FBG sensor patch that is not in contact with the trachea. Intracuff pressure measurements performed using a commercial manometer agreed well with the FBG contact pressure measurements. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.Item Open Access Highly sensitive optical fibre long period grating biosensor anchored with silica core gold shell nanoparticles(Elsevier, 2015-08-22) Marques, L.; Hernandez, F. U.; James, Stephen W.; Morgan, S. P.; Clark, M.; Tatam, Ralph P.; Korposh, SergiyAn optical fibre long period grating (LPG), modified with a coating of silica core gold shell (SiO2:Au) nanoparticles (NPs) deposited using the layer-by-layer method, was employed for the development of a biosensor. The SiO2:Au NPs were electrostatically assembled onto the LPG with the aid of a poly(allylamine hydrochloride) (PAH) polycation layer. The LPG sensor operates at the phase matching turning point to provide the highest sensitivity. The SiO2:Au NPs were modified with biotin, which was used as a ligand for streptavidin (SV) detection. The sensing mechanism is based on the measurement of the refractive index change induced by the binding of the SV to the biotin. The effect on sensitivity of increasing the surface area by virtue of the SiO2:Au nanoparticles’ diameter and film thickness was studied. The lowest measured concentration of SV was 2.5 nM, achieved using an LPG modified with a 3 layer (PAH/SiO2:Au) thin film composed of SiO2 NPs of 300 nm diameter with a binding constant of View the MathML sourcek=1.7(pM)-1, sensitivity of View the MathML source6.9nm/ng/mm2 and limit of detection of 19 pg/mm2.Item Open Access Sensitive protein detection using an optical fibre long period grating sensor anchored with silica core gold shell nanoparticles(SPIE, 2014-12-31) Marques, L.; Hernandez, F. U.; Korposh, Sergiy; Clark, M.; Morgan, S. P.; James, Stephen W.; Tatam, Ralph P.An optical fibre long period grating (LPG), modified with a coating of silica gold (SiO2:Au) core/shell nanoparticles (NPs) deposited using the layer-by-layer (LbL) method, was employed for the development of a bio-sensor. The SiO2:Au NPs were electrostatically assembled onto the LPG with the aid of a poly(hydrochloride ammonium) (PAH) polycation layer. The LPG sensor operates at the phase matching turning point to provide the highest sensitivity. The SiO2:Au NPs were modified with biotin, which was used as a ligand for streptavidin (SV) detection. The sensing mechanism is based on the measurement of the refractive index change induced by the binding of the SV to the biotin. The lowest detected concentration of SV was 19 nM using an LPG modified with a 3 layer (PAH/SiO2:Au) thin film.