{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,15]],"date-time":"2025-10-15T17:29:07Z","timestamp":1760549347889,"version":"build-2065373602"},"reference-count":16,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2013,4,2]],"date-time":"2013-04-02T00:00:00Z","timestamp":1364860800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Micromachines"],"abstract":"<jats:p>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.<\/jats:p>","DOI":"10.3390\/mi4020138","type":"journal-article","created":{"date-parts":[[2013,4,2]],"date-time":"2013-04-02T12:52:56Z","timestamp":1364907176000},"page":"138-148","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["Pushing the Limits of Electrical Detection of Ultralow Flows in Nanofluidic Channels"],"prefix":"10.3390","volume":"4","author":[{"given":"Klaus","family":"Mathwig","sequence":"first","affiliation":[{"name":"MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede,  The Netherlands"}]},{"given":"Serge","family":"Lemay","sequence":"additional","affiliation":[{"name":"MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede,  The Netherlands"}]}],"member":"1968","published-online":{"date-parts":[[2013,4,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"550","DOI":"10.3390\/mi3030550","article-title":"Micromachined thermal flow sensors\u2013A review","volume":"3","author":"Kuo","year":"2012","journal-title":"Micromachines"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"225","DOI":"10.3390\/mi3020225","article-title":"Micromachined flow sensors in biomedical applications","volume":"3","author":"Silvestri","year":"2012","journal-title":"Micromachines"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"635","DOI":"10.1007\/s00348-003-0610-4","article-title":"A novel system for measuring liquid flow rates with nanoliter per minute resolution","volume":"34","author":"Westin","year":"2003","journal-title":"Exp. Fluids"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Mathwig, K., Mampallil, D., Kang, S., and Lemay, S.G. (2012). Electrical cross-correlation spectroscopy: Measuring picoliter-per-minute flows in nanochannels. Phys. Rev. Lett., 109.","DOI":"10.1103\/PhysRevLett.109.118302"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"11471","DOI":"10.1021\/ja902331u","article-title":"Fast electron transfer kinetics probed in nanofluidic channels","volume":"131","author":"Zevenbergen","year":"2009","journal-title":"J. Am. Chem. Soc."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1262","DOI":"10.1039\/c2lc21104a","article-title":"Response time of nanofluidic electrochemical sensors","volume":"12","author":"Kang","year":"2012","journal-title":"Lab Chip"},{"key":"ref_7","unstructured":"Liang, H., Nam, W.J., and Fonash, S.J. (2008, January 1\u20135). A Novell Parallel Flow Control (PFC) System for Syringe Driven Nanofluidics. 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