Red Emitting Phthalocyanines Used As Fluorescent Probes For The Analysis Of Biomacromolecules And Premilinary Invesitgation Of Their Applications In Bioimaging

Long wavelength emitting fluorescent probes can effectively avoid the interference of background fluorescence and scattered light, as compared with the conventional fluorescent reagents, because the natural and synthetic materials have little absorption or emission in long-wavelength region. Phthalocyanine compounds include one class of fluorescent reagents emitted in red region. This work focus on the applications of red emitting phthalocyanine fluorescent probes on the analysis of biomacromolecules and imaging detection, it is divided into five chapters.In chapter1, the developments of fluorescent probes in red and near-infrared region were reviewed, followed by the introduction of phthalocynine compounds about their molecular structure, characteristic of molecular spectra, methods for preparation and the main application areas of these compounds.In chapter2, this work aims at developing a novel method for rapid determination of chondroitin sulfate. The fluorescence of tetrasulpnonated aluminum phthalocyanine (AIS4PC), a anionic metal phthalocyanine, was quenched dramatically by cationic surfactant in which contains a positively-charged head with a conjugated structure and a long carbon chain as tail through the formation of a almost non-fluorescent association complex. It was found that the ion-association complex (AIS4PC-CPB) emitted strong fluorescence in the presence of chondroitin sulfate, due to the ability of chondroitin sulfate to shift the association equilibrium of the ion-association complex that leaded to the release of AlS4PC, thus resulting in an increase in the fluorescence of AlS4Pc. Based on the above-mentioned phenomenon, a novel method for quantitative determination of chondroitin sulfate in practical samples was developed using the ion-association phthalocyanine complex as a fluorescent probe emitting at red-region. Two anionic surfactants quenching the fluorescence of AlS4Pc with high efficency were screened. It was found that different sensitivity and linear range for the determination of chondroitin sulfate were obtained using the two surfactants as quenchers. Therefore, two determination systems were investigated separately.In chapter3, the main idea of this part of work is to develop a novel method for rapid determination of lysozyme. It was found that the fluorescence of the cationic aluminum phthalocyanine, a red-region fluorescence probe, was extremely quenched in acidic media in the presence of low concentrations of anionic mucopolysaccharide heparin (HP) bearing anionic sulfonic acid groups, due to induced aggregation. The almost non-fluorescent substrate was degraded into small molecule fragments by the hydrolysis of lysozyme, hence, the phthalocyanine molecules aggregated in HP were released, resulted in significant fluorescence recovery of the reaction system. This phenomenon bases the principle of the proposed method. The reaction mechanism was discussed employing fluorescence spectroscopy and steady-state fluorescence anisotropy techniques. Factors which affected the determination were investigated. The established method has been used to the analysis of real samples of lysozyme, the results are in well agreement with those determined by a conventional turbidimetric method.In chapter4, preliminary investigation on the the application of fluorescent phthalocyanines for the imaging of potent fingerprints are carried out. Seven fluorescent phthalocyaniens were screened,and factors which affected the detection were investigated. Among phthalocyanine compounds having been investigated, A1(SO2>Cl)4TSP showed the most effective results for the imaging of potent fingerprints.In the final chapter, the possibility of fluorescent phthalocyanines for in vivo imaging of cells was prmilinarily investigated. The purpose of this work is to study the location behavior of fluorescent phthalocyanines inside cells. Microinjection techinique was established for injecting fluorescent phthalocyanines into cells directly. Preliminary results of the study showed that fluorescent phthalocyanine compounds have the great potential to be new fluorescent probes for cell imaging in v1vo.