In this paper, a novel signal processing circuit which can be used for the measurement of H+ ion and urea concentration is presented. A potentiometric method is used to detect the concentrations of H+ ions and urea by using H+ ion-selective electrodes and urea electrodes, respectively. The experimental data shows that this measuring structure has a linear pH response for the concentration range within pH 2 and 12, and the dynamic range for urea concentration measurement is in the range of 0.25 to 64 mg/dL. The designed instrumentation circuit possesses a calibration function and it can be applied to different sensing electrodes for electrochemical analysis. It possesses the advantageous properties of being multi-purpose, easy calibration and low cost.
References
[1]
Clark, L.C.; Lyons, C. Electrode system for continuous monitoring in cardiovascular surgery. Ann. N.Y. Acad. Sci. 1962, 102, 29–45. 14021529
[2]
Diamond, D. Principles of Chemical and Biological Sensors; Wiley: New York, NY, USA, 1998.
Bergveld, P. Thirty years of ISFETOLOGY: What happened in the past 30 years and what may happen in the next 30 years. Sens. Actuators B Chem. 2003, 88, 1–20, doi:10.1016/S0925-4005(02)00301-5.
[5]
Chi, L.L.; Chou, J.C.; Chung, W.Y.; Sun, T.P.; Hsiung, S.K. Study on extended gate field effect transistor with tin oxide sensing membrane. Mater. Chem. Phys. 2000, 63, 19–23, doi:10.1016/S0254-0584(99)00184-4.
[6]
Webster, J.G. Medical Instrumentation Application and Design; Wiley: New York, NY, USA, 2010.
Iniewski, K. VLSI Circuits for Biomedical Applications; Artech House Inc.: Norwood, MA, USA, 2008.
[9]
Lin, C.Y.; Lai, Y.H.; Balamurugan, A.; Vittal, R.; Lin, C.W.; Ho, K.C. Electrode modified with a composite film of ZnO nanorods and Ag nanoparticles as a sensor for hydrogen peroxide. Talanta 2010, 82, 340–347, doi:10.1016/j.talanta.2010.04.047. 20685476
[10]
Yin, L.T.; Chou, J.C.; Chung, W.Y.; Sun, T.P.; Hsiung, S.K. Separative structure ISFETs on a glass substrate. Proc. SPIE 1999, 3987, 543–551.
[11]
Pan, C.W.; Chou, J.C.; Sun, T.P.; Hsiung, S.K. Development of the tin oxide pH electrode by the sputtering method. Sens. Actuators B Chem. 2005, 108, 863–869, doi:10.1016/j.snb.2004.11.033.
[12]
Sanagi, M.M.; Ling, S.L.; Nasir, Z.; Hermawan, D.; Ibrahim, W.A.; Abu Naim, A. Comparison of signal-to-noise, blank determination, and linear regression methods for the estimation of detection and quantification limits for volatile organic compounds by gas chromatography. J. AOAC Int. 2009, 92, 1833–1838. 20166602
[13]
New 8FX MB95430H Series Datasheet. Available online: http://www.fujitsu.com/downloads/MICRO/fma/mcu/MB95430H_DS_Mar2011.pdf (accessed on 4 April 2011).
