Determination of Diclofenac on a Dysprosium Nanowire- Modified Carbon Paste Electrode Accomplished in a Flow Injection System by Advanced Filtering

Sensors

Parandis Daneshgar²  Parviz Norouzi²  Mohammad Reza Ganjali²  Rasoul Dinarvand¹ 

[1] Medical Nanotechnology Research Center, Faculty of Pharmacy, University of Tehran Medicinal Sciences, Tehran, Iran; E-Mail:;Center of Excellence in Electrochemistry, Department of Chemistry, University of Tehran, Tehran, Iran; E-Mails:

关键词: Fast Fourier Transformation;    square wave voltammetry;    carbon paste electrode dysprosium nanowire;    diclofenac;    oxidation-reduction;   

DOI  :  10.3390/s91007903

来源: mdpi

【 摘 要 】

A new detection technique called 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), which is generated by a redox processes, is fast, which makes the method suitable for most applications involving flowing electrolytes. The carbon paste electrode was modified by nanostructures to improve sensitivity. Synthesized dysprosium nanowires provide a more effective nanotube-like surface [1-4] so they are good candidates for use as a modifier for electrochemical reactions. The redox properties of diclofenac were used for its determination in human serum and urine samples. The support electrolyte that provided a more defined and intense peak current for diclofenac determination was a 0.05 mol L⁻¹ acetate buffer pH = 4.0. The drug presented an irreversible oxidation peak at 850 mV vs. Ag/AgCl on a modified nanowire carbon paste electrode which produced high current and reduced the oxidation potential by about 100 mV. Furthermore, the signal-to-noise ratio was significantly increased by application of a 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, C_DL of 2.0 × 10⁻⁹ M and an LOQ of 5.0 × 10⁻⁹ M were found for the determination for diclofenac. A good recovery was obtained for assay spiked urine samples and a good quantification of diclofenac was achieved in a commercial formulation.

【 授权许可】

CC BY   
© 2009 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland.