Title of article :
Sinusoidal voltammetry:: a frequency based electrochemical detection technique
Author/Authors :
Brazill، نويسنده , , Sara A and Bender، نويسنده , , Sharin E and Hebert، نويسنده , , Nicole E and Cullison، نويسنده , , John K and Kristensen، نويسنده , , Eric W and Kuhr، نويسنده , , Werner G، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2002
Pages :
14
From page :
119
To page :
132
Abstract :
Sinusoidal voltammetry is an electrochemical technique, which uses a large amplitude sinusoid as the potential waveform and performs data analysis in the frequency domain. When the amplitude of the applied potential waveform is large (i.e. >50 mV) the current–potential behavior of the electrochemical interface is extremely non-linear. As a result the faradaic response exhibits signal intensity at higher order harmonics of the fundamental excitation frequency. In contrast, the major source of noise, due to the capacitive charging current, is primarily linear and the vast majority of its intensity remains at the fundamental frequency. The dramatic difference in the frequency response between these signals can be exploited in many ways to enhance both the signal-to-noise ratio and selectivity of an electrochemical measurement. The extent of faradaic signal distribution to the harmonics of the fundamental excitation frequency is dependant on many standard voltammetric parameters. In addition to enhanced sensitivity at the higher harmonics, redox species with different electrochemical properties (e.g. E°, number of electrons, electron transfer rate constant, etc.) can be detected selectively based on their unique ‘fingerprint’ frequency response. The experimental parameters (e.g. Eswitch, scan rate, excitation potential window amplitude, etc.) can be optimized, as well as the frequency and phase angle to achieve the best selectivity for the analyte of interest.
Keywords :
Sinusoidal voltammetry , Experimental methods , microelectrode
Journal title :
Journal of Electroanalytical Chemistry
Serial Year :
2002
Journal title :
Journal of Electroanalytical Chemistry
Record number :
1668360
Link To Document :
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