Pringsheim, Erika and Terpetschnig, Ewald and Wolfbeis, Otto S. (1997) Optical sensing of pH using thin films of substituted polyanilines. Analytica Chimica Acta 357, pp. 247-252.
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Polyanilines (PANIs) are viable materials for use in optical sensing of pH. Thin films of substituted PANI readily deposit on the inner walls of polystyrene cuvettes when a substituted aniline is chemically polymerized in hydrochloric acid solution. The films have been characterized by absorption spectra which have maxima between 600 and 810 nm, except for halogenated or p-substituted anilines. They undergo pH-dependent changes in their absorption spectra in the physiological pH range, and substituents exhibit a strong effect on pKa values. PANI films are advantageous over indicator-based pH sensor films in that they are not based on the use of indicator dyes, are compatible with LED and diode laser light sources, and can easily be prepared. Copolymers of aniline and anthranilic acid are shown to be useful supports for immobilization of the enzyme urease, and the resulting films can be used to detect urea. Films of substituted PANIs are redox-active and also respond to reductants such as ascorbic acid and hydrogen sulfide.
|Institutions:||Chemistry and Pharmacy > Institut für Analytische Chemie, Chemo- und Biosensorik > Chemo- und Biosensorik (Prof. Otto S. Wolfbeis)|
|Keywords:||pH sensor; Polyanilines; Optical sensor; NIR sensor|
|Subjects:||500 Science > 540 Chemistry & allied sciences|
|Created at the University of Regensburg:||Unknown|
|Deposited On:||07 Jun 2011 11:15|
|Last Modified:||21 Jul 2011 02:14|