Simultaneous Voltammetric Measurement of Ascorbic Acid, Epinephrine, Uric Acid and Tyrosine at a Glassy Carbon Electrode Modified with Nanozeolite-Multiwall Carbon Nanotube

Abstract

In this study, incorporation of iron ion-doped natrolite nanozeolite, multi-wall carbon nanotubes into chitosan-coated glassy carbon electrode for the simultaneous determination of ascorbic acid, epinephrine, uric acid and tyrosine is studied. The results show that the combination of multi-wall carbon nanotubes and iron ion-doped natrolite zeolite causes a dramatic enhancement in the sensitivity of ascorbic acid, epinephrine, uric acid and tyrosine quantification. The sensor gave the separated and sharp voltammetric responses of analytes in four well-defined linear sweep voltammetry peaks. Under the optimum conditions, the calibration curve were linear up to 1.82 × 10-3, 3.15 × 10-3 , 1.50 × 10-4 and 6.29 × 10-4 M with detection limits 1.82 × 10-6, 1.33× 10-6, 4.09 × 10-8 and 2.01× 10-7 M (S/N= 3) for ascorbic acid, epinephrine, uric acid and tyrosine, respectively. The analytical performance of this sensor has been evaluated for simultaneous detection of four analytes in human serum and urine samples.

Keywords

• Simultaneous determination
• Nanozeolite
• Multiwalled carbon nanotube
• Biocompounds