Fabrication of agar-gel microelectrodes and their application in the studyof ion transfer across the agar-water 1,2-dichloroethane interface

In this paper, we describe a simple procedure to make agar-gel microelectro des by filling micropipettes. These microelectrodes were used to study K+ t ransfer across the agar-water \ 1,2-dichloroethane interface facilitated by dibenzo-18-crown-6 (DB18C6), and the transfer of tetraethylammonium (TEA()). The results observed were similar to those obtained at micro-liquid \ l iquid interfaces. The effect of various amounts of agar in the aqueous phas e was optimized and 3% agar was chosen based on the potential window and so lidification time. The different shapes of micro-agar-gel electrodes were p repared in a similar way. The fabricated agar-gel microelectrodes obey the classical micro-disk steady-state current equation, which is different from the behavior of a normal micropipette filled with aqueous solution without silanization. (C) 2001 Elsevier Science B.V. All rights reserved.