Journal of Solid State Electrochemistry

, Volume 4, Issue 4, pp 234–236

Copper(II) ion-selective microelectrochemical transistor


  • Vibha Saxena
    • Physics Department, The Institute of Science, 15 Madam Cama Road, Mumbai 400035, India
  • Vinay Shirodkar
    • Physics Department, The Institute of Science, 15 Madam Cama Road, Mumbai 400035, India
  • Rajiv Prakash
    • Analytical Toxicology, Industrial Toxicology Research Centre, M. G. Marg, PO Box 80, Lucknow 226001, India e-mail:

DOI: 10.1007/s100080050201

Cite this article as:
Saxena, V., Shirodkar, V. & Prakash, R. J Solid State Electrochem (2000) 4: 234. doi:10.1007/s100080050201


A device has been developed for the measurement of copper(II) ions (Cu2+) in aqueous medium. The device reported here is an electrochemical transistor which consists of two platinum electrodes separated by 100 μm spacing and bridged with an anodically grown film of polycarbazole. Polycarbazole film (undoped form) is observed to be highly selective for the Cu(II) ions. In a completed device, the conductivity of the polycarbazole film changes on addition of Cu(II) ions. The change in conductivity is attributed to the conformational changes in the polymer phase on occupation of the Cu(II) ions, without affecting electron/proton transfer. The device turns on by adding 2.5 × 10−6 M Cu(II) ions and reaches a saturation region beyond 10−4 M Cu(II) ion concentrations. In the above concentration range, the device response [ID vs. log Cu(II) ion concentration] is linear. The selectivity of the device for other metal ions such as Cu(I), Ni(II), Co(II), Fe(II), Fe(III), Zn(II) and Pb(II) is also studied.

Key words Copper(II) ionsPolycarbazoleElectrochemical transistor

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© Springer-Verlag Berlin Heidelberg 2000