The Preparation And Analytical Characteristics Of Mono And Bis-porphyrins As Molecular Recognition Carriers Used In Electrochemical And Optical Sensor Technology

Improving the selectivity of a sensor is recognized as a difficult problem in the field of chemical sensing technology. Searching for novel molecular recognition ionophores with high selectivity has attracted large attention of current analytical chemistry. Porphyrins and metalloporphyrins are recognized as perfect host for molecular recognition owing to their diversity, their rigid molecular structures, the position and direction of the substituents on the porphyrin ring being controllable, as well as the variety of metal ligands of the metalloporphyrins. The study of the chemical sensing characteristics of porphyrins and metalloporphyrins is an active area all the while. Searching for novel porphyrin derivatives with high selectivity as the molecular recognition ionophores for chemical sensors, therefore, remains task of theoretical and practical significance. Taking the aforementioned problems as research objectives, this thesis mainly accomplished four research tasks and its contents include following: In part one, a series of novel porphyin derivatives were investigated as molecular recognition ionophores, and their electrochemical sensing characteristics were studied. Several PVC membrane ion-sensitive electrodes with anti-Hofmeister selective pattern were prepared. (1) A BF4 sensitive electrode based on chloro[tetra(m-amino- phenyl)porphinato]-manganese as neutral carrier has been prepared. The relationship between the structure of central metal ion of metalloporphyrins and the response characteristics of their electrodes was studied and the experimental conditions optimized. The electrode is applied to the determination of fluoroborate in electroplating solutions. (2) A BF4 sensitive electrode based on p-oxo-bis[tetra(p- chlorophenyl)porphinatomanganese] has been prepared. The interaction between BF4 and bismetalloporphyrin was investigated using UV-Vis spectrophotometry. III ) Several ji-oxo-bismetalloporphyrins with different substituents on the benzene rings were compared for potentiometric response characteristics. It was concluded that the relationship between electrode performance and substituting group constant a for substitution of the benzene rings on p-oxo-bismetalloporphyrins was positively interrelated. (3) An p-oxo-bismetalloporphyrin based salicylate-sensitive electrode has been proposed and its response compared with that of monometalloporphyrin counterpart. The mechanism of the electrode response has been investigated. The electrode was preliminarily applied to the determination of salicylate in urine. (4) An ethacrynic acid sensitive electrode based on 2,4-pentanedionato[meso- tetraphenylporphinatolterbium has been obtained. The effect of the structure of lanthanide porphyrin complexes to the electrode response was studied. The response mechanism of the electrode was investigated using UV-Vis spectrophotometry and lipophilic ion additive experiment. (5) A berberine-sensitive electrode based on free glycosylated porphyrin has been prepared. The composition of the electrode membrane has been optimized. The response mechanism of the electrode was investigated. The electrode was applied to the determination of berberine in pharmaceutical tablets. In part two, the optical chemical sensing characteristics of the obtained porphyin derivatives were investigated. They were used as c...