The Interaction Mechanism Of 1,10-Phenanthroline Complexes Of Ferrum(III) And The Studies On Fluorescence Fiber-Optic DNA Biosensor

Deoxyribonucleic acid (DNA) is the basic material in the most of lives, which exits in all kinds of organism extensively, and it is the main material base of some lives course, such as storing, duplicating and transmitting hereditary information, etc.. Metal complexes play a key role in the course of a lot of lives, and they are important probes for studying some molecular such as nucleic acid. To study DNA biosensor, two 1,10-phenanthroline complexes of ferrum(III) were synthesized and characterized. The interactions between the complexes and salmon sperm DNA were studied by fluorescence spectrum, UV-Vis spectrum and electrochemical methods. With two 1,10-phenanthroline complexes of ferrum(III) as the hybridization indicators, the fluorescence fiber-optic DNA biosensors with covalently immobilized DNA modified optical fiber have been prepared.(1) With 1,10-phenanthroline and 1,10-phenanthroline ramification using as ligands, two complexes imidazo [f]1,10-phenanthroline ferrum(III) ([Fe(phen)2 IP]·3ClO4·2H2O) and p-Hydroxyphenylimidazo [f] 1,10-phenanthroline ferrum(III) ([Fe(phen)2 PHPIP]·3ClO4·2H2O) have been synthesized successfully. The structures of these novel complexes have been determined by means of IR and EA, respectively. The fluorescent property of the two complexes were demonstrated by 3-D fluorescence spectrum.(2) The interactions mechanism between two metal complexes and salmon sperm DNA have been studied by means of fluorescence spectrum, UV-Vis spectrum and electrochemical methods, respectively. The results show that the interaction mode between [Fe(phen)₂IP]³⁺ and DNA is intercalation, binding ratio is 1:1 and binding constant is 4.00×102 L·mol-1. The interaction mode between [Fe(phen)₂PHPIP]³⁺ and DNA is intercalation too, binding ratio is 1:2 and binding constant is 1.02×103 L0.5·mor-0.5。(3) With the two complexes as the hybridization indicators respectively, the fluorescence fiber-optic DNA biosensors with covalently immobilized DNA modified optical fiber have been prepared. The fluorescence fiber-optic DNA biosensors can be used to the recognition of complementary ssDNA segment. Using [Fe(phen)₂IP]³⁺ as hybridization indicator, the complementary ssDNA could be quantified over the ranges from 1.25×10-8mol·L^-1 to 1.50×l0-7 mol·L^-1 and a detection limit of 1.35×10-9 mol·L^-1 . Using [Fe(phen)₂PHPIP]³⁺ as hybridization indicator, the complementary ssDNA could be quantified over the ranges from 4.98×10-7 mol·L^-1 to 4.88×10-6 mol·L^-1 and a detection limit of 1.08x 10-7 mol·L^-1 .