| In this article, copper (Ⅱ) complex of Luteolin and Imidazo[4,5-f] [1,10] phenanthroline ferrum (Ⅲ) were synthesized, whose structures were characterized by IR and EA methods. Cyclic voltammetry (CV) and fluorescence spectroscopy techniques were used to study the interaction between these compounds and salmon sperm DNA to optimize conditions. These sensors were prepared by immobilizing single-stranded DNA probes on Platinum nanoparticles or Silver nanoparticls combined with carbon nantubes modified glassy carbon electrodes (GCEs) and using different electroactive indicators to measure the hybridization events between the DNA probes and their complementary DNA fragments. The electrochemical DNA biosensor might have potential application in disease testing or novel anticancer drug designing. This masteral dissertation constitutes by four parts besides the preface.(1) The interaction between Luteolin and double-stranded salmon sperm DNA (dsDNA) in pH 5.0 Britton-Robinson (B-R) buffer solution was studied by cyclic voltammetry and fluorescence spectroscopy at GCE surface. The experimental conditions for incubation of dsDNA and Luteolin such as buffer solution, pH, reaction time, scan rate and dsDNA concentrations were optimized to pursue the maximum anodic peak current difference. It was revealed that Luteolin could bind with salmon sperm DNA strands mainly by intercalation mode. The binding number of Luteolin for each salmon sperm dsDNA chain and equilibrium constant of the binding reaction were calculated to be 2 : 1 and 3.33 x 1010L2·mol-2, respectively.(2) Copper (Ⅱ) complex of Luteolin C30H18CuO12 (abbreviated by CuL2) was synthesized and characterized using elemental analysis and IR spectroscopy. The interaction between CuL2 and double-stranded DNA was investigated by cyclic voltammetry and fluorescence spectroscopy. The experimental conditions for incubation of dsDNA and Luteolin such as buffer solution, pH, reaction time and scan rate were optimized to pursue the maximum anodic peak current difference.The experiment results showed that CuL2 presented an excellent electrochemical activity on GCE and could intercalate into the double helix of double-stranded DNA. The binding number of Luteolin for each salmon sperm dsDNA chain and equilibrium constant of the binding reaction were calculated to be 3 : 1 and 3.80×1014 L3·mol-3, respectively.(3) A novel and sensitive electrochemical DNA biosensor has been developed for the detection of DNA hybridization. The biosensor was proposed by using CuL2 as an electroactive indicator based on multi-walled carbon nanotubes/silver nanoparticles (Ag/MWCNTs) modified glassy carbon electrode. In this method, the 4-aminobenzoic acid (4-ABA) and Ag nanoparticles was covalently grafted on MWCNTs in the proper order by electrochemical action, which could enhance the sensitivity of the hybridization detection. The target ss-oligonucleotides of the human hepatitis B virus (HBV) was quantified in a linear range from 3.23×10"12 mol·L-1 to 5.31×10-9 mol·L-1 (r = 0.9983) with a detection limit of 6.46×10-13 mol·L-1 (3σ, n = 11).(4) Imidazo [f] 1,10-phenanthroline ferrum(Ⅲ) ([Fe(phen)2 IP]·3ClO4·2H2O) has been synthesized and characterized using IR and EA. Using Fe(phen)2 IP]·3ClO4·2H2O as an indicator, DNA biosensors were prepared based on platinum nanoparticles and MWCNTs that were deposited on the surface of a glassy carbon electrode. The response of Ptnano/ MWCNTs /GCE was significantly higher as compared with that prepared based on a MWCNTs /GCE electrode. The target ss-oligonucleotides of the human hepatitis B virus (HBV) was quantified in a linear range from 1.13×10-11 mol·L-1 to 1.13×10-9 mol·L-1 (r = 0.9892) with a detection limit of 5.56×10-12 mol·L-1 (3σ, n = 11). |
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