The Study On Several Novel Fluorescence Probes And Sensors

The immobilization methods of fluorescent indicators play an important role in the fabrication of the fluorescent probes or sensors. In this paper, several novel techniques of immobilizing indicators are developed in order to anchor the indicators in supporting materials of the sensing layers. Some new fluorescent probes and sensors are prepared using these techniques, and they are utilized to determine some medicines and toxic materials in the environments. The main contents are as follows:(1) A kind of polymer particles encapsulated naphthaleneboronic acid (NBA) was prepared via an oil-in-water emulsion polymerization procedure. The resulting polymer particles were used to determine ornidazole. Their capacities to resist photobleaching and interferences were improved as compared to those of free naphthaleneboronic acid. When the concentration of the polymer particles was fixed at 0.2 mg ml -1, it showed a linear response toward ornidazole in the range of 8.0×10^-7 mol l^-1 to 8.0×10^-5 mol l^-1 with a detection limit of 5.0×10^-7 mol l^-1.(2) A novel fluorescence probe was prepared by using emulsion polymerization for covalent immobilization of the indicator dyes. First, a terminal double bond was introduced into 3-amino-9-ethylcarbazole (AEC) via methacryloyl chloride to obtain the compound, 3-(N-methacryloyl)amino-9-ethylcarbazole (MEC). Second, MEC was copolymerized with butyl methacrylate to prepare the MEC-immobilized polymer particles. The resultant polymer particles were used as a fluorescence probe, which was almost free of dye leaching, and had higher photostability in comparison with free AEC. The probe was used to determine picric acid, showing a linear response to picric acid in the range from 9.3×10^-7 4.7×10^-5 mol l^-1 with good selectivity. The interference arising from some inorganic salts and organic materials was no more than 5.0%. Results of recovery experiments indicated that the recovery ratios of picric acid were from 96.2% to 103.2%.(3) 1-Amino-4-allyloxyanthraquinone (AAA) was synthesized via the reaction of allyl bromide with 1-amino-4-hydroxyanthraquinone, and then covalently immobilized on surface-modified glass slides. An AAA-immobilized optical sensor was obtained. Experiments showed that the emission fluorescence intensity of the sensor decreased as the concentration of ornidazole increased when the sensor contacted with solutions of ornidazole. This property could be used to determine the content of ornidazole. Results indicated that the sensor had some advantages such as rapid response, high...