de Marcos, Susana and Wolfbeis, Otto S. (1996) Optical sensing of pH based on polypyrrole films. ANALYTICA CHIMICA ACTA, 334 (1-2). pp. 149-153. ISSN 0003-2670, 1873-4324
Full text not available from this repository.Abstract
An optical sensor for pH is presented which is based on the use of a thin polypyrrole (PPy) film obtained by chemical oxidation of pyrrole and deposited as a <1 mu m film on the walls of a polystyrene cuvette. The spectrum of PPy displays strong absorption in the near infrared at around 900 nm, and a characteristic minimum at around 550 nm. The shape and intensity of the spectrum are pH-dependent between pH 6 and 12, the minimum being shifted to shorter wavelengths at higher pH, and the absorbance of the longwave band increasing in the range 600-900 nm range. The apparent pK(a) is around 8.6, but once exposed to a pH 6, the films need to be reconditioned with 0.1 M HCl in order to give the same response to pH. The films are an interesting alternative to indicator-based pH sensor films in that they do not require a dye to be immobilized, are fully compatible with LED and diode laser light sources, and can easily be prepared.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | ENERGY-TRANSFER; SENSOR; BEHAVIOR; SUPPORT; FIBERS; optical sensors; sensors; polypyrrole; infrared spectrometry |
| Subjects: | 500 Science > 540 Chemistry & allied sciences |
| Divisions: | Chemistry and Pharmacy > Institut für Analytische Chemie, Chemo- und Biosensorik |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 25 May 2023 12:25 |
| Last Modified: | 25 May 2023 12:25 |
| URI: | https://pred.uni-regensburg.de/id/eprint/51341 |
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