Optical-fibre sensors for blood gases and pH, based on porous glass tips
✍ Scribed by Avraham Bromberg; Judith Zilberstein; Salomon Riesemberg; Eyal Benori; Ernesto Silberstein; Joseph Zimnavoda; Gad Frishman; Amnon Kritzman
- Publisher
- Elsevier Science
- Year
- 1996
- Tongue
- English
- Weight
- 982 KB
- Volume
- 31
- Category
- Article
- ISSN
- 0925-4005
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✦ Synopsis
Optical-fibre sensors have been developed for the determination of blood gases and pH. Chemical binding of pyrenebutyric acid and 7hydroxy-4-methylcoumarine-3-acetic acid to a porous tip of a fused silica fibre produces a sensitive measuring device for molecular oxygen and pH. Insertion of the pH sensor into a solution of bicarbonate, entrapped within a polypmpylene membrane, yields apCO2 sensor. Excitation of the oxygen-sensor tip within the range 340-360 nm yields emission with a maximum intensity at 460 nm. An intensity ratio ---10 between signals measured in pure gas-phase nitrogen and oxygen is obtained. Excitation of the sensitive tip within the range 360-380 nm yields emission with a maximum intensity at 457 4-3 nm. The excitation spectrum is red shifted about 19-30 nm relative to that oblained in solution. The maximum intensity of the excitation spectrum for the acidic form of the bound coumarine derivative is at 356+ 3 nm, whereas for the basic form it is at 380 + 3 nm. The apparent pK of the bound coumarine derivative is 7.45 + 0.30. The bias and the precision for pOe determinations in blood samples are about -! and + 1.5 ton', respectively. For pH determinations, the respective values are about 0.02 and 0,04 pH units and for pCO2 about 1 and 2.5 ton'. The sensors described are suited for production on an industrial scale.