The Aggregation And Room Temperature Phosphorescence Behavior And Application Of Metal-porphyrin In The Organized Microenvironment

The characteristic behavior of room temperature phosphrescence of metal-porphyrin in the organized micro-environment was investigated. Metal-porphyrin can demonstrate an excellent room temperature phosphorescence (RTP) in the tested organized medium. On the basis of this premise, RTP was used to investigate the aggregation of metal-porphyrin under the influence of anionic sodium dodecyl sulfate (SDS) (Chapter 2); For compared reasons, the RTP and aggregation behavior of anion or cation porphyrin were tested in the different organized medium (Chapter 3); especially we concentrated our attention on the obvious enhancement of Pd-porphyrin RTP by alkaline earth metal in the organized sodium deoxycholate (NaDC) aggregates solution (Chapter 4); we also use this RTP probe to test the Bovine Serum Albumin (BSA) and concanavalin A (ConA), the experimetal result is very good (Chapter 5); Finally, the highly ordered structures self-assembled by NaDC under metal-ion-mediation was investigated and proved (Chapter 6).Chapter 1:Reviewed the character and apply of metal-porphyrin in RTP. Especially the Pd/Pt porphyrin often used as RTP probe because of its long life time, longer wavelength, big stokes shift. At the same time, we introduced some conditions of microenvironment which RTP needed.Chapter 2:RTP was used as a useful analytical tool to investigate the interaction behavior between tetracationic meso-tetrakis (4-trimethylaminophenyl) porphyrin palladium (Pd-TAPP) and SDS. UV-Vis absorption and resonance light scattering (RLS) were further applied to characterize the system. It presumably suggested that nonspecific self-aggregates among porphyrins formed, which resulted in an energy split of 2550 cm-1 of RTP excited state when the concentration of Pd-TAPP was higher enough. Pd-TAPP can change from free monomer/non-specific aggregate to H-aggregate and then out-micellized monomer/non-specific aggregate as a function of SDS concentration. RTP signal enhanced obviously and excitation spectrum blue-shifted with 1580 cm-1 in energy with respect to energy of free Pd-TAPP monomer identified that 1:4 electrostatic interaction between Pd-TAPP and SDS led to the formation of the premicellar porphyrin-surfactant H-aggregates, since Coulombic repulsive force between cationic porphyrin was decreased by the interaction with SDS. The RLS spectrum indicated that the H-aggregates were multiple porphyrin units. UV-Vis spectra revealed that cationic groups of monomers/nonspecific aggregates of Pd-TAPP were electrostatic attracted in favor of the surface of anionic micelles but not encapsulated within apolar regions of SDS micelles when the concentration of SDS was above its critical micelle concentration (CMC).Chapter 3:Comparison of cationic porphyrin with anionic porphyrin's RTP behavior in different organized medium helps us to explain the interaction theory between the different ionic porphyrin with ionic surfactants which the organized medium impact on the RTP intensity. There are three reasons for RTP intensity increased:(a) the role of electrostatic force increases the rigidity and orderliness of the microenvironment system; (b) the hydrogen bonds increase the rigidity and orderliness of the microenvironment system; (c) provides more rigid and hydrophobic space for the micro-environment. For the tested system of Pd-TAPP and SDS, palladium-tetra-anionic meso-tetrakis (4-carboxyphenyl) porphyrin (Pd-TCPP) and CTAB or CPDB, before the formation of surfactant micelles, electrostatic force play an important role; and after micelles formed, the electrostatic forces, as well as hydrophobic space play the role together. Non-ionic surfactant to anionic Pd-TCPP in the RTP enhancement can be attributed to the ether bond of Brij-35 interact to the carboxyl group of Pd-TCPP by the formation of hydrogen bonds; while in Brij-35 micelle, the system of hydrogen bonding and hydrophobic space formation played the joint action; RTP enhancement of DNA, RNA on Pd-TAPP is due to electrostatic and hydrophobic interactions; RTP enhanced of BSA on Pd-TCPP is mainly due to hydrogen bonds. Thus we can conclude that, even if the micro-environment system is ordered and rigid, without the interaction between phosphor and organized system, RTP intensity will not enhanced; only the interaction between phosphor and medium exist, phosphorescence intensity can increase.Chapter 4:The organized system of sodium deoxycholate (NaDC) could induce Pd-porphrins to emit room temperature phosphorescence (RTP). Among three Pd-porphyrins, Pd-TAPP obtained the strongest RTP intensity, two anionic Pd-porphyrins such as Pd-TCPP and Pd-tetra-anionic meso-tetrakis (4-sulfonatophenyl) porphyrin (Pd-TSPP) obtained less. However, it was found that addition of alkaline earth metal (AEM) into NaDC could dramatically enhance the RTP intensity of Pd-porphyrins, especially for Pd-TCPP. Among the three AEMs, the combination of NaDC and Ca2+could produce the highest increase of the RTP intensity of Pd-TCPP by 203.7 times more than without adding of Ca2+, and of the three AEMs this capability of intensification was Ca2+> Ba2+>Mg2+ in order. Further study on the structure indicated that a regular fan-like structure formed with the presence of an AEM in NaDC micelle aggregated solution, and this structure provided a well organized, rigid, and very stabile micro-environment in solution which are the critical factors for obtaining liquid-RTP. From the experiments, it turned out that a complex microcrystal formed with AEM standing as a bridge connecting Pd-TCPP and NaDC, and the tighter the connection between Pd-TCPP and NaDC, the higher the intensity of the obtained RTP would be. Of the three AEMs tested, the Ca2+ showed the highest affinity with Pd-TCPP and NaDC so that the complex microcrystal bridged by Ca2+ obtained the most intensive RTP. The structure of the NaDC and AEM was also investigated.Chapter 5:RTP probe of metal-porphyrin was used to investigate the interaction between Pd-TCPP and BSA and ConA. RTP Intensity of Pd-TCPP can be quenched by BSA and ConA with static quenching, which indicated an obvious interaction between two. The binding constant of this interaction was 1.82×106 L·mol-1 or 3.33×104 L·mol-1, respectively. UV-vis spectroscopy and resonance light scattering spectroscopy were also used to testify the conclusion. RTP of Pd-TCPP can be used as a probe to test BSA, the liner range is 1×10-9 g·mL-1×10-4 g·mL-1, detection limit is 2.6×10-11 g·mL-1, relative standard deviation 2.3%.Chapter 6:A simple and visual method is used to observe the interesting structure aggregates of NaDC by optical micrograph. NaDC self-assembled into fan-like structural aggregates with uniform size and shape. Additional metal ions led the aggregates transfer from fan-like to fractal aggregates. The fractal aggregates might provide an insight into understanding the formation of a gallstone because fractal structures were found in human beings gallstones.