Fabrication of Fluorescent Hybrid Nanoparticles and Their Specific Ion and Molecule Detection Applications

Abstract

Various nanoprobe systems are being developed to explore their potential in biomedical fields, with many applications to the diagnosis or monitoring of various diseases. There are many advantages of nano-size probes for the application in biomedical field. First, the scale of cell and tissue structures is meaningful. Since most nanoprobes are about 10—500nm which are generally over 100 fold smaller than cells. Second, the building blocks of nanoprobes like proteins, carbohydrates, nucleic acids, synthetic polymers or small inorganic particles are generally smaller than about several scores of nanometers. Third, nanoprobes have potential for wide application because they can easily contain useful molecules such as imaging agents, active targeting moieties, or drugs by simple loading or conjugation. Consequently, it is still challenging to produce fluorescent hybrid nanoparticles for detecting and imaging target analytes in living systems. This dissertation describes the three different ways in the synthetic methodology of fluorescent hybrid nanoparticles. First, PAN nanomaterials as novel bioimaging agents without additional fluorophores were developed by ultrasound induced emulsion polymerization, and it could be applied for the fluorescence sensors of copper ion and cell imaging. Second, a dual emission Au-PAN NPs sensor was prepared for sensitive detection of mercury ions in aqueous solution. The Au-PAN nanoparticles showed significant intensity change by addtion of mercury ions and higher binding affinity toward mercury ion than other metal ions. Lastly, a novel fluorescent Au-GQDs nanoparticle was synthesized for use as a probe that can selectively detect Cys in living cells. The dual emission fluorescence peak ratio changed when the Au-GQDs nanoparticles reacted with Cys. This fluorescence behavior was highly specific for Cys. Most importantly, these novel approaches can be used as an alternative tool for specific ions and molecule detection in environmental condition, and may offer an opportunity for the further investigation of industrial applications, and might be expanded to allow the fluorescence sensor applications of hybrid nanoparticles in a wide range of areas.