COLL 401 |
| We have lithographically fabricated fluidic nanodevices consisting of a solution-filled cavity bounded by two parallel electrodes which are separated by as little as 20 nm. This geometry permits highly efficient redox cycling (repeated reduction and oxidation), yielding a dramatic amplification of the electrochemical current from reversible species located inside the device. Advantages of the nanofabrication approach include reproducibility, ease of integration with other nanofluidic devices, and enhanced stability which allows carrying out precision electrical measurements. To illustrate the latter, we studied the current fluctuations in the device and showed that their frequency spectrum can be completely understood by considering the diffusion of independent redox molecules, without fitting parameters. Our device has important advantages for electrochemical sensors, in particular enhanced sensitivity and suppression of the interference from irreversible species. We illustrate the latter through the straightforward voltammetric detection of catechol despite interference from a 500:1 excess of ascorbic acid. |
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Electrochemistry-Enabled Nano S&T
2:00 PM-5:15 PM, Wednesday, April 9, 2008 Morial Convention Center -- Rm. 229, Oral
Division of Colloid & Surface Chemistry |