[Fluorescent characters of optical BOD sensing film].

We characterized an optical BOD sensing film used to immobilize three kinds of microorganisms from seawater. The sensing film for BOD measurement consists of an optical oxygen sensor and the microorganisms immobilized on poly(vinyl alcohol) ormosils matrix. The fluorescent responses of the BOD sensing film were obviously affected by the thickness of the oxygen film and the concentration of microorganisms in the film. Some other experimental conditions, such as pH, measurement temperature, and the concentration of sodium chloride, were studied. BOD values estimated by this optical BOD sensing film correlate well with those determined by the conventional BOD5 method for seawater samples.