Scanning Electrochemical Microscopy. 32. Gallium Ultramicroelectrodes and Their Application in Ion-Selective Probes

• Published in: Analytical chemistry (Washington) Vol. 68; no. 15; pp. 2651 - 2655
• Main Authors: Wei, Chang, Bard, Allen J., Kapui, Imre, Nagy, Géza, Tóth, Klára
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.08.1996
• Subjects: Chemical elements; Chemistry; Electrochemistry; Exact sciences and technology; General and physical chemistry; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Ions; Microscopes; Physics; Scanning probe microscopes, components and techniques; Fabrication; Microprobe; Gallium; Scanning probe microscopy; Amperometry; Electrochemistry; Selectivity; Imagery; Potassium ions; Ultramicroelectrode
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac9512362

Gallium ultramicroelectrodes for amperometric measurements in scanning electrochemical microscopy were fabricated by introduction of liquid Ga into drawn glass micropipets. Cyclic voltammetry of Ru(NH3)6 3+ and the use of this species for SECM imaging is described. Double-barrel micropipet tips with a Ga amperometric electrode and an ion-selective (K+) potentiometric probe can also be constructed. This probe was used to image the K+ activity near a 20-μm-diameter lumen of a glass capillary.