Amperometric biosensors based on carboxylated multiwalled carbon nanotubes-metal oxide nanoparticles-7,7,8,8-tetracyanoquinodimethane composite for the determination of xanthine.
A comparison of the analytical performances of two xanthine biosensors, based on the use of different metal oxide nanoparticles (MONPs: Co3O4or Fe3O4)-modified carboxylated multiwalled carbon nanotubes (c-MWCNTs)-7,7',8,8'-tetracyanoquinodimethane (TCNQ)-chitosan (CHIT) composite, is discussed. Xanthine oxidase (XOD) enzyme was covalently attached to c-MWCNTs/MONPs/TCNQ/CHIT/GCE via N-ethyl-N'-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxy succinimide (NHS) chemistry and the electrode surface was further modified with Nafion in order to minimize the effect of possible interfering substances. The results showed that analytical performance of the Fe3O4based biosensor was better than the Co3O4based biosensor. The linear working range, limit of detection and sensitivity were found to be 1.9×10-6-2.3×10-4M, 0.20μM (S/N=3), 25.07μAmM-1cm-2for the Fe3O4based biosensor and 1.9×10-6-1.2×10-4M, 0.36μM (S/N=3), 13.24μAmM-1cm-2for the Co3O4based biosensor, respectively. The purposed biosensors were applied in the determination of xanthine in coffee samples, and satisfactory results were obtained.
Ankara University, Faculty of Science, Department of Chemistry, Ankara, Turkey.
Berna
B
Dalkıran
Ankara University, Faculty of Science, Department of Chemistry, Ankara, Turkey. Electronic address: erdenpe@gmail.com.
Pınar
P
Esra Erden
Ankara University, Faculty of Science, Department of Chemistry, Ankara, Turkey.
Esma
E
Kılıç
D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002264:Carboxylic Acids / Q000737:chemistry; D003035:Cobalt / Q000737:chemistry; D003069:Coffee / Q000737:chemistry; D004563:Electrochemistry; D004566:Electrodes; D052203:Ferrosoferric Oxide / Q000737:chemistry; D057230:Limit of Detection; D008958:Models, Molecular; D008968:Molecular Conformation; D053758:Nanoparticles / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009570:Nitriles / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D019820:Xanthine / Q000032:analysis*
D002264:Carboxylic Acids; D003069:Coffee; D037742:Nanotubes, Carbon; D009570:Nitriles; D010087:Oxides; C013703:tetracyanoquinodimethane; D019820:Xanthine; D003035:Cobalt; C060728:cobalt oxide; D052203:Ferrosoferric Oxide
Co(3)O(4) nanoparticles; Fe(3)O(4) nanoparticles; Mediator; Multiwalled carbon nanotubes; Xanthine biosensor