Solid Contact Micropipette Ion Selective Electrode II: Potassium Electrode for SECM and In Vivo Applications

Micropipette ion selective electrodes are very small, but fragile, short-life time sensors with very high resistance. Their high resistance is a draw back considering application in scanning electrochemical microscopy (SECM) and in life sciences. New, low resistance potassium micropipette electrodes were prepared, and applied. The electrode contains solid internal contact made of a carbon fiber lowered down all the way close to the orifice of the micropipette. The internal contact potential was kept constant by applying a doped, electrochemically prepared PEDOT coating on the fiber surface. The electrode performed well in in vivo experiments both in plant and animal tissue without capacitance neutralization and in SECM.