ELECTRO-ANALYSIS OF LIQUIDS AND SENSING ELEMENTS FOR USE THEREIN

摘要

PCT No. PCT/GB92/01017 Sec. 371 Date Apr. 29, 1994 Sec. 102(e) Date Apr. 29, 1994 PCT Filed Jun. 5, 1992 PCT Pub. No. WO92/21961 PCT Pub. Date Dec. 10, 1992.A sensing element, for use in determining the presence and/or concentration of a species in a solution, comprises a flat insulating substrate (10) having at least one thin metallic electrode (16) deposited on it and overlaid with an insulating layer (20). The electrode (16) and insulating layer (20) bridge a weakening groove (12) formed in the substrate. Immediately before use, the element is broken along the groove to expose a cross-sectional surface (24) of the element, and thus a cross-sectional working surface (26) of the electrode. The thickness (T) of the element is comparable to or less than the concentration boundary layer thickness of the solution. This exposed working surface is the only part of the electrode in contact with the solution. In use, the element can be vibrated so as to improve its sensitivity.