Optical sensor based on sensitive polymer layer

摘要

In chemical, oil, and food industries, there are still higher requirements on miniaturization of optical sensors fora concentration measurement of gases e.g. a CO_2, O_2,and NH_3. The paper deals with development of miniaturisedoptical sensor for an aqueous carbon dioxide measurement using a sensitive polymer layer. The optical sensor moduleconsists of two parts, a remission sensor and a removable layered structure (with incorporated dyed polymer) which isclosely placed on the surface of a remission sensor. A dyed polymer film is used as an optical-chemical transducerworking on a principle of colour changes caused by a chemical reaction of an analyte and indicator dye. A novelremission sensor module was developed for an evaluation of the spectral absorption changes of sensitive polymer layer.The remission sensor module composed of LED diodes located in a central cavity of the sensor module and PIN diodessituated around the cavity. The LEDs emit light with optimised wavelengths and irradiate the polymer film. Lightresponse (the changes of the spectral absorption) of the irradiated polymer film is detected by PIN diodes. A colour shiftis further analyzed and evaluated by electronics without using a photometer.