Voltammetric and separations-based sensors for neurochemical analysis

A new carbon microelectrode developed by low temperature catalytic pyrolysis of ethylene on nickel is presented. This low temperature catalytic pyrolysis method enables pulled glass capillaries to be used as support material to make smaller carbon electrodes than previously possible. This method holds the promise to make ultrasmall probes for dynamic measurements inside single nerve cells.;Static measurements of electroactive species inside single nerve cells has been accomplished with capillary electrophoresis and amperometric detection. A copper wire amperometric detector for nonelectroactive species separated by capillary electrophoresis is presented. With further optimization this detection method has the potential for static analysis of single nerve cells with capillary electrophoresis.;Development of a detection technique based on electrogenerated chemiluminescence is presented. This method, which involves the oxidation of luminol and subsequent luminescence, promises ultralow detection limits since no light source is required for excitation of the sample solute. Subfemtomole detection limits for luminol have been achieved in a nonoptimized system. Fundamental studies concerning the influence of the concentration of hydrogen peroxide and the magnitude of the applied potential on the efficiency of the electrochemical reaction is presented.;The electrogenerated chemiluminescence detection in capillary electrophoresis is applied to the separation and detection of amines derivatized with an isoluminol derivative. In addition, preliminary studies concerning ECL detection of amino acids derivatized with the new labeling reagent 4-isocyanatophthalhydrazide is shown.