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Pushing the Limits of Electrical Detection of Ultralow Flows in Nanofluidic Channels
MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands
* Author to whom correspondence should be addressed.
Received: 11 December 2012; in revised form: 30 January 2013 / Accepted: 20 March 2013 / Published: 2 April 2013
Abstract: This paper presents improvements in flow detection by electrical cross-correlation spectroscopy. This new technique detects molecular number fluctuations of electrochemically active analyte molecules as they are transported by liquid flow through a nanochannel. The fluctuations are used as a marker of liquid flow as their time of flight in between two consecutive transducers is determined, thereby allowing for the measurement of liquid flow rates in the picoliter-per-minute regime. Here we show an enhanced record-low sensitivity below 1 pL/min by capitalizing on improved electrical instrumentation, an optimized sensor geometry and a smaller channel cross section. We further discuss the impact of sensor geometry on the cross-correlation functions.
Keywords: flow detection; electrochemical sensor; nanofluidics; cross-correlation; nanochannel; redox cycling
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Mathwig, K.; Lemay, S.G. Pushing the Limits of Electrical Detection of Ultralow Flows in Nanofluidic Channels. Micromachines 2013, 4, 138-148.
Mathwig K, Lemay SG. Pushing the Limits of Electrical Detection of Ultralow Flows in Nanofluidic Channels. Micromachines. 2013; 4(2):138-148.
Mathwig, Klaus; Lemay, Serge G. 2013. "Pushing the Limits of Electrical Detection of Ultralow Flows in Nanofluidic Channels." Micromachines 4, no. 2: 138-148.