- Thionine immobilized in crosslinked chitosan films

LEANDRO GERBINO; MIRIAM STRUMIA; RODRIGO IGLESIAS; ANA BARUZZI

SENSORS AND ACTUATORS B-CHEMICAL

ELSEVIER SCIENCE SA

Año: 2008 p. 455 - 461

0925-4005

Redox and acid–base properties of thionine immobilized in crosslinked chitosan films are analyzed. The experimental conditions for the preparation of the films are described. Results obtained with cyclic voltammetry, spectroelectrochemistry and spectrophotometry indicate that the immobilized dye retains the redox and acid–base activity of free thionine. An acid dissociation constant (Ka) for the immobilized dye ofKa) for the immobilized dye of Ka = 2.7×10−11 was obtained. Due to the stable and reversible pH dependent optical signal of the studied film, this membrane can be used as a building component of an optical pH sensor. Due to the stable and reversible pH dependent optical signal of the studied film, this membrane can be used as a building component of an optical pH sensor. a = 2.7×10−11 was obtained. Due to the stable and reversible pH dependent optical signal of the studied film, this membrane can be used as a building component of an optical pH sensor.