title: Dual pO2/pCO2fibre optic sensing film.
abstract: A fibre optic multi-sensor has been developed for biomedical sensing applications using a tip coating solution sensitive to both oxygen and carbon dioxide. An oxygen sensitive phosphorescence quenching complex based on platinum octaethylporphyrin (PtOEP) was combined with a carbon dioxide sensitive phosphorescence compound based on 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS). When excited by blue light (470 nm), the resultant coating had two fluorescent peaks at 515 nm (green) and 645 nm (red) which responded to partial pressure of CO2and O2respectively. The sensor was tested in vitro and shown to be able to measure CO2and O2simultaneously and in real time, with calibration constants of 0.0384 kPa-1and 0.309 kPa-1respectively. The O2sensitive peak received some overlap from the 515 nm peak (0.38% of peak intensity) as well as some cross-sensitivity (maximum, 5.1 kPa pCO2gave a measurement equivalent to 0.43 kPa of O2, a ratio of 0.08 : 1). However, these effects can be subtracted from measurements and no significant cross-sensitivity or overlap was seen in CO2measurements from O2. This novel compound presents great potential for use in medical sensors and we expect it to be important to a wide range of future applications.
authors.affiliation: Research Centre for Biomedical Engineering, University of London, Northampton Square, London, EC1V 0HB, UK. john.davenport.1@city.ac.uk.
authors.forename: John J
authors.initials: JJ
authors.lastname: Davenport
authors.forename: Michelle
authors.initials: M
authors.lastname: Hickey
authors.forename: Justin P
authors.initials: JP
authors.lastname: Phillips
authors.forename: Panayiotis A
authors.initials: PA
authors.lastname: Kyriacou