Acta Phys. -Chim. Sin. ›› 2010, Vol. 26 ›› Issue (11): 2920-2926.doi: 10.3866/PKU.WHXB20101117

• ELECTROCHEMISTRY • Previous Articles     Next Articles

Mathematical Model and Circuit Realization to Improve Chronoamperometry

CHEN Xu-Hai1,2, CHEN Jing-Hua3, PAN Hai-Bo2, LI Yu-Rong2, DU Min2, LIN Xin-Hua3   

  1. 1. College of Electrical Engineering and Automation, Fuzhou University, Fuzhou 350000, P. R. China;
    2. Fujian Key Laboratory of Medical Instrumentation &Pharmaceutical Technology, Fuzhou 350000, P. R. China;
    3. Department of Pharmaceutical Analysis, Faculty of Pharmacy, Fujian Medical University, Fuzhou 350000, P. R. China
  • Received:2010-05-27 Revised:2010-07-27 Published:2010-10-29
  • Contact: DU Min E-mail:fjkeylab@163.com
  • Supported by:

    The project was supported by the National High Technology Research and Development Program of China (863) (2008AA02Z433, 2006AA02Z4Z1), International Science and Technology Cooperation Project of China (2009DFA32050) and Natural Science Foundation of Fujian Province, China (2008J1005).

Abstract:

To overcome the disadvantages of chronoamperometry we report a novel electrochemical method where a peak current is quickly generated for the current vs time curve by changing the waveform of voltage excitation in the working electrode. In particular, we derived a mathematical model to illustrate the principle of this method and it can also be used to demonstrate that the peak current is linear with regards to the concentration of the target substance. Moreover, we developed a device with an improved electrochemical circuit using a control element from control theory to change the waveform of voltage excitation. The improved circuit can detect the peak automatically without a precise sample time. Finally, the device was used to study the electrochemical behavior of K3[Fe(CN)6] and 3,3',5,5'- tetramethylbenzidine (TMB). We show that the method has a better signal to noise ratio and higher sensitivity than chronoamperometry. The obtained peak current is linear with regards to the concentration of the target substance and can be quickly detected without a precise sample time.

 

Key words: Chronoamperometry, Electrochemical analyser, Peak detector, Inertial element

MSC2000: 

  • O646