Abstract
The presented invention relates to a needle-shaped ion-selective solid contact microelectrode with the length of the measuring point preferably but not limited to equal or less than 10 micron, particularly 0.5 - 10 micron, a method for producing such an electrode and use of an ion-selective solid contact microelectrode as a working electrode in different scanning measuring systems, such as SECM, SIET, MIFE and others, for measuring activity (concentration) of different ions in the modes of three-dimensional gradient scanning, plane two-dimensional scanning, vertical or horizontal profiling, one point measurements or any other point by point measurements over an active surface. For example, the present invention aims to substitute the glass-capillary microelectrodes used in localized measurements.
The microelectrode of presented invention differs in its principles of construction and production opposed to that of solid-contact ion-selective electrodes. The invention describes a needle-shaped rigid electrically-conductive substrate (1); an insulation layer (4), except in the tip of said substrate (3); an electrically-conductive layer (6); and a layer of ion-selective membrane (7).
Innovative aspects & main advantages
This new dry microelectrode that can be used to measure the location and concentration of ions can also be utilized for biomedical research applications. It is more robust than the current microelectrodes (which use glass instead of metal). Its stability is also higher, and most likely not be more costly. The current microelectrodes made of glass (with fluid - ion - inside) are not a commercial success because they do not resist to transportation.
The advantages of the microelectrodes of presented invention are robustness, longer life time, faster time of response and wider range of linear functioning in terms of ions’ concentration. These advantages cover all basis characteristics of ion-selective electrodes.
Applications
Laboratory equipments and biomedical research.
From the commercial point of view the subject matter of presented invention is of interest for the companies which sell (and produce) the micro electrodes for localised measurements, reagents and liquid cocktails for ion-selective electrodes. Selected companies which produce equipment for localised electrochemistry and reagents for ion-selective electrodes:
Applicable Electronics Inc., USA (www.applicableelectronics.com).
Uniscan Instruments, UK (www.uniscan.com).
Microprobe Inc., USA (www.microprobes.com).
World Precision Instruments, USA (www.wpiinc.com).
Sigma-Aldrich (www.sigmaaldrich.com).
Cleangrow, UK (www.cleangrow.com).