A dysprosium nanowire modified carbon paste electrode for determination of levodopa using fast Fourier transformation square-wave voltammetry method

Abstract

A new detection technique called the fast Fourier transform square-wave voltammetry (FFT SWV) is based on measurements of electrode admittance as a function of potential. The response of the detector (microelectrode) is fast, which makes the method suitable for most applications involving flowing electrolytes. The carbon paste electrode was modified by nanostructures to improve better sensivity. The redox property of Diphenhydramin was used for determination of it in human serum and urine samples. Synthesized dysprosium nanowires make more effective surface like nanotubes [1-4] so they are good candidates for using as a modifier for electrochemical reactions. The drug presented one irreversible oxidation peaks at 1080mV vs. Ag/ AgCl by modified Nanowire carbon paste electrode which produced high current and reduced the oxidation potential about 300mV. Furthermore, signalto-noise ratio has significantly increased by application of discrete fast Fourier Transform (FFT) method, background subtraction and two-dimensional integration of the electrode response over a selected potential range and time window. To obtain the much sensivity the effective parameters such as frequency, amplitude and pH was optimized. As a result, LOD of 4.0 ×10-11 mol l -1 and an LOQ of 8.0× 10 -11 mol l -1 were found for determination for Diphenhydramin. A good recovery was obtained for assay spiked urine samples and a good quantification of Diphenhydramin was achieved in a commercial formulation.

A Selective Simultaneous Determination of Levodopa and Serotonin Using a Glassy Carbon Electrode Modified with Multiwalled Carbon Nanotube/Chitosan Composite

“…Lev unlike Ser shows a couple of redox peaks. The peak positions were similar to previously reports for individual determinations of Lev [59] and Ser [17]. The effect of scan rate on the oxidation responses of Lev and Ser at the MWCNTs-CHT/GCE was investigated in the 10-1000 mV s À1 scan rate range using cyclic voltammetry (not shown).…”

Square‐Wave Voltammetry: A Review on the Recent Progress

“…The kinetic parameters of the electrochemical reaction or yRNA have been evaluated from SW voltammetric response. A fast Furrier transformed square-wave voltammetry has been applied to detect the amino acid levodopa that is precursor required by the brain to produce dopamine [139]. With the help of this technique, l-dopamine has been detected in urine and human serum in micromolar concentration range by using microelectrode.…”

Electrochemical studies of nevirapine, an anti-HIV drug, and its assay in tablets and biological samples

“…For the determination of NVP in plasma, spiked serum samples were prepared following the procedure reported earlier [17]. Serum samples obtained from healthy individuals (after obtaining their written consent) were stored frozen until assay.…”