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

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 x l0(-3), 3.15 x 10(-3), 1.50 x 10(-4) and 6.29 x 10(-4) M with detection limits 1.82 x lO(-6), 1.33x lO(-6), 4.09 x 10(-8) and 2.01 x 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.