Detection of adenosine <i>in vitro</i> and <i>in vivo</i> using fast-scan cyclic voltammetry at the same carbon-fiber microelectrode.

<p>(A) <i>In vitro</i> calibration of adenosine. A 3-D color plot (bottom) depicts time on the <i>x</i>-axis, potential on the <i>y</i>-axis, and current in false color. The primary oxidation occurs at 1.4 V (large green oval in center of color plot) and the secondary oxidation occurs at 1.0 V (green/purple oval below center oval). The dashed white line on the color plot denotes where the background subtracted cyclic voltammogram (CV, top) is obtained. (B) <i>In vivo</i> spontaneous, transient adenosine event. The 3-D color plot and CV shows primary and secondary oxidation peaks that match the <i>in vitro</i> calibration.