ANYL 13 |
| There are many physiologically important gas molecules. For instance, nitric oxide (NO) is well known for its crucial functions as a vasodilator, a neurotransmitter, etc. An analogous gas molecule, carbon monoxide (CO) has been discovered to perform similar functional roles to those of NO. Therefore, it is of great interest to measure these gases in biological environments. In this presentation, we will demonstrate the development of an electrochemical dual gas sensor to detect two different gas molecules (any two among NO, CO, and O2) simultaneously, directly, and quantitatively. The novel planar amperometric sensor is composed of two platinized Pt microdisk electrodes as working electrodes and a deposited Ag layer reference electrode on the sensor body covered with a polymeric gas permeable membrane. The sensor is characterized in terms of its analytical performance (i.e., sensitivity, selectivity, detection limit, response time, stability, etc.). The dual sensor is also examined for its feature as a tip probe in scanning electrochemical microscopy (SECM), a modern useful tool capable of providing local chemical information/mapping of any microstructure. Thus, the location-dependent concentrations of these gas molecules (possibly generated from the biological sample surfaces) can be simultaneously investigated by SECM with the dual sensor. For this purpose, the miniaturization of this gas sensor (with tip diameters on the order of ~ 10 mm) is accomplished while maintaining high sensitivity and a quite fast response time. |
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Analytical Approaches: Electroanalytical Chemistry
8:30 AM-11:40 AM, Sunday, 10 September 2006 Moscone Center -- Room 124, Oral
Division of Analytical Chemistry |