Valinomycin-based K+ selective microelectrodes with low electrical membrane resistance

Neurosci Lett. 1987 Feb 24;74(2):221-6. doi: 10.1016/0304-3940(87)90153-4.


A valinomycin-based membrane phase for microelectrodes with relatively low electrical membrane resistances is described. Microelectrodes with tip diameters of about 1 micron exhibit resistances of about 10(10) omega. Extremely high K+ selectivities are obtained, e.g. a rejection of Na+ by a factor of 5000 and of acetylcholine by a factor of 3400. At a constant background of 140 and 500 mM Na+, the detection limit of the K+ sensor is at 1.6 X 10(-5) and at 2.5 X 10(-5) M K+, respectively.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Electric Conductivity
  • Electrochemistry / instrumentation*
  • Microelectrodes*
  • Neurophysiology / instrumentation*
  • Potassium / metabolism*
  • Valinomycin*


  • Valinomycin
  • Potassium