Fig. 2.

Plots showing wireless detection of adenosine using WINCS at a CFM in vitro. A: Pseudocolor plot obtained during a 20 second flow cell injection of 5 µM adenosine, exhibiting 3D information. The x axis, y axis, and color gradient indicate time, voltage applied at the CFM, and current (I) detected from the CFM, respectively. The FSCV waveform was applied from -0.4 V to +1.5 V and back to -0.4 V at 400 V/second every 100 msec. A green oval surrounded by a purple ring first appears around +1.5 V after the adenosine injection, and this represents the first oxidative peak of adenosine. A second oxidative peak around +1.0 V occurs after the appearance of the first oxidative peak. B: Graph showing current versus time traces for the first and second peak oxidative currents (taken along horizontal black and red dotted lines respectively on 2A). C: A representative background-subtracted folded voltammogram of adenosine, showing 1st and 2nd oxidative peaks (taken along vertical solid black line in 2A). D: Picture of the WINCS device chipset relative to a United States quarter dollar coin. WINCS: Wireless Instantaneous Neurotransmitter Concentration System, CFM: carbon-fiber microelectrodes, FSCV: fast scan cyclic voltammetry.