Drop-Coated Polyaniline Composite Conductimetric pH Sensors

This work describes the fabrication and development of a polyaniline based conductimetric pH sensor. Two types of drop coated polyaniline films were investigated and it was found that the undoped emeraldine base polyaniline produces the best electrical response to pH. The results obtained show that the lowest conductance of these films occurs at the lowest pH value (pH2), with the conductance increasing with increasing pH. It is thought that this response is due to effects from the polymer binder, which is used to increase adhesion between the pH-sensitive film and the substrate.

[1]  I. Rubinstein.  Voltammetric pH measurements with surface-modified electrodes and a voltammetric internal reference , 1984 .

[2]  L. Bousse,et al.  The role of buried OH sites in the response mechanism of inorganic-gate pH-sensitive ISFETs , 1984 .

[3]  Sophie Lakard,et al.  Potentiometric pH sensors based on electrodeposited polymers , 2005 .

[4]  Ari Ivaska,et al.  pH sensitivity of polyaniline and its substituted derivatives , 2002 .

[5]  A. Shaun Francomacaro,et al.  Microfabricated conductimetric pH sensor , 1995 .

[6]  R. Koncki,et al.  Screen-printed ruthenium dioxide electrodes for pH measurements , 1997 .

[7]  K. Ihokura,et al.  The tin dioxide gas sensor , 1993 .

[8]  Li Qingwen,et al.  Response of nanosized cobalt oxide electrodes as pH sensors , 2000 .

[9]  C. Ahn,et al.  On-Chip Electrochemical Analysis System Using Nanoelectrodes and Bioelectronic CMOS Chip , 2006, IEEE Sensors Journal.

[10]  C. Zheng,et al.  ; 0 ; , 1951 .

[11]  M. Esashi,et al.  Methods of isfet fabrication , 1981 .

[12]  A. Karyakin,et al.  Potentiometric biosensors based on polyaniline semiconductor films , 1996 .

[13]  P. Malkaj,et al.  pH electrodes constructed from polyaniline/zeolite and polypyrrole/zeolite conductive blends , 2006 .

[14]  T. Troczynski,et al.  A resistive gas sensor based on undoped p-type anatase , 2005 .

[15]  Theodore H. Geballe,et al.  Low-Frequency Conductivity Due to Hopping Processes in Silicon , 1961 .

[16]  K. Schoch,et al.  Conducting polymers , 1992, [1991] Proceedings of the 20th Electrical Electronics Insulation Conference.

[17]  P. Chandrasekhar.  Conducting polymers, fundamentals and applications : a practical approach , 1999 .

[18]  C. Ahn,et al.  pH sensor using nano electrodes in organic semiconductor , 2004, The 26th Annual International Conference of the IEEE Engineering in Medicine and Biology Society.

[19]  Michel de Labachelerie,et al.  Miniaturized pH biosensors based on electrochemically modified electrodes with biocompatible polymers. , 2004, Biosensors & bioelectronics.

[20]  H. Salavagione,et al.  Tuning the electroactivity of conductive polymer at physiological pH , 2007 .

[21]  J. D. Thomas,et al.  Devices for ion-sensing and pX measurements , 2001 .

[22]  Ali Eftekhari,et al.  pH sensor based on deposited film of lead oxide on aluminum substrate electrode , 2003 .

[23]  P Bergveld,et al.  Development of an ion-sensitive solid-state device for neurophysiological measurements. , 1970, IEEE transactions on bio-medical engineering.