Optical sensors: Development and applications in the UV -visible, near- and mid -infrared spectroscopy

Ekwutosi Anastasia Okafor, University of Rhode Island


Different applications of sol-gel using spectrophotometric methods have been investigated. The ultimate goal is to develop new sensors with this class of material for novel applications. This was made possible by developing techniques for its preparations, handling and developing methods of incorporating sensitive materials to meet these novel demands. Simultaneous determinations of reaction processes have been achieved by incorporating other novel conductive polymers in the sol-gel matrix. The conductive polymers employed were the single and the double strands polyaniline. The sensors were mainly used for the determination of glucose in aqueous media. Comparisons of the different sensors built were made. UV-visible and near infrared spectroscopy have been mainly used to analyze the various areas of interest in the sample. Mid-infrared spectroscopy was limited in its use due to opaqueness of the samples in this region. The sensors were found stable for use for one year if left as bulk; but when made as thin films, they were stable for daily use.^ In the second part of this work, a search algorithm known as the "Mix-match" algorithm was used to identify mixtures of organic compounds using UV-visible spectrometer and for various dye mixtures in environmental media. This algorithm was successfully used in identifying the various odd colors produced by the combinations of these dyes and successfully identified the mixtures of the organic compounds. The outcome here was that this algorithm proved to be superior to other search methods such as the Euclidean distance search method. The algorithm was able to detect problems where they existed and showed its ability to identify components in mixtures without prior knowledge of the compositions. The use of Fourier Transform process helped in improving the searching performance and in reducing the required time. ^

Subject Area

Chemistry, Analytical|Chemistry, Organic

Recommended Citation

Ekwutosi Anastasia Okafor, "Optical sensors: Development and applications in the UV -visible, near- and mid -infrared spectroscopy" (1998). Dissertations and Master's Theses (Campus Access). Paper AAI9902573.