4498

4232

كارشناسي ارشد

شيمي تجزيه

اصفهان: دانشگاه صنعتي اصفهان، دانشكده شيمي

1387

پانزده، 83، [II]ص: نمودار، جدول

ص.ع به: فارسي و انگيسي

علي اصغر انصافي، تقي خياميان

10/3/1388

بهزاد رضايي، محمدتقي جعفري

شيمي

ID4232

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Electrochemical Biosensor Based on DNA for Evaluation of Antioxidant Capacity and Electrocatalytic Determination of Isoproterenol Maryam Dadkhah m dadkhah2007@yahoo com March 7 2009 04 07 Department of Chemistry Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisors Ali Asghar Ensafi and taghi KhayamianEmail ensafi@cc iut ac irEmail taghi@cc iut ac irAbstract An electrochemical biosensor has been developed evaluation of antioxidant capacity In this biosensor the damage a ds DNA modified graphite electrode has been monitored by measurement electrochemicalsignal from of couple DNA Ru bpy 32 before and after treatment whit antioxidant by SWV method Theoxidizing mediator Ru bpy 33 is electrogenerated on the graphite electrode that oxidize modified DNA onthe surface and damage it the decreasing in the redox signal of the DNA by Ru bpy 23 is proinhibited byantioxidant In this research several parameters affect on the intensity and electrochemical peak current wereoptimized Then the catalytic rate constant was measured for reaction of Ru bpy 33 with DNA andRu bpy 33 with rutin and ascorbic acid by chronoamperometry and SWV methods An electrochemical method is described for the cyclic voltammetric determination of isoproterenol Themethod is based on catalyst effect of p chloranil as a mediator for the electrocatalytic oxidation ofisoproterenol on the surface of modified carbon paste electrode The oxidation of isoproterenol occur atpotentials about 600 mV less positive than with the unmodified carbon paste electrode at pH 10 5 Under theoptimal conditions the peaks current was linear with concentration of isoproterenol in the range of 30 0 to1500 0 mol L 1 The detection limits S N 3 was 19 95 mol L 1 isoproterenol with relative standarddeviations of less than 3 The chronoamperometry was used to determine the catalytic rate constant for thecatalytic reaction and diffusion coefficient also was measured The proposed method has been successfullyapplied to the determination of isoproterenol in pharmaceutical and human serum samples Key Words Antioxidants DNA electrochemical biosensor Ru bpy 32 DNA damage Isoproterenol p chloranil Modified carbon paste electrode

علي اصغر انصافي، تقي خياميان

بهزاد رضايي، محمدتقي جعفري