الفهرس | Only 14 pages are availabe for public view |
Abstract Part (I): deals with the interaction of fluoroquinolones (ciprofloxacin, norfloxacin, ofloxacin, pefloxacin and levofloxacin) with DNA in solution have been investigated by means of voltammetry and spectroscopy. The results show that the values of binding constant of fluoroquinolone drugs with DNA obtained through the changes of the anodic peak current, and their values are, 30900, 31000, 32300, 32000 and 32500 M1 respectively. Or changes of absorption and their values are, 36000, 30200, 38300, 36500 and 34400 M1 receptively.Part (II): includes voltammrtric behavior of fluoroquinolones on DNAmodified carbon paste electrode. The binding of fluoroquinolones (ciprofloxacin, norfloxacin, ofloxacin, pefloxacin and levofloxacin) with DNA immobilized on the surface of an anodically activated carbon paste electrode was exploited for designing a sensitive biosensor for fluoroquinolones. The response was optimized with respect to preconcentration time, ionic strength, drug concentration, reproducibility and other variables. The results show that the anodic peak response of fluoroquinolone drugs at DNAmodified electrode surface has been affected with medium in which the intercalation occurs. However, the intercalation in acetate buffer pH 5 is better than in phosphate buffer pH7.Part (III): includes analytical application for proposed method for the determination of levofloxacin as a typical example for fluoroquinolones. concentration in the range 5.0 <U+00D7> 10<U+2013>7 ~ 5.0 <U+00D7>10<U+2013>6 mol/L, with a detection limit of 1.0 <U+00D7> 10<U+2013>7 mol/L. Direct and simple determination of levofloxacin in urine was established with no manipulation of urine sample other than dilution 1:10. The detection limit of the method is 25 <U+F06D>g ml1of levofloxacin in urine and the relative standard deviation of 10 measurements was found to be 2.2 %. The method was validated using HPLC as a reference method. |