Application of optical fibres in oxidation-reduction titrations

Abstract The paper presents recent advances in the development of an optical fibre system for determination of the end-point in redox titration. A new method for reagent immobilization based on the entrapment of the molecules in micropores is described. This method seems to be independent of both the physical and chemical properties of the reagent. As a practical application we have tested an optrode based on the use of a colourimetric indicator. This indicator was N , N ′-diphenylbenzidine. A low-cost optoelectronic system consists of a bifurcated optical fibre bundle with a light emitting diode as a light source and a silicone photodiode as a photodetector.