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Asymmetric Membrane for Digital Detection of Single Bacteria in Milliliters of Complex Water Samples

Lin, Xingyu and Huang, Xiao and Zhu, Yanzhe and Urmann, Katharina and Xie, Xing and Hoffmann, Michael R. (2018) Asymmetric Membrane for Digital Detection of Single Bacteria in Milliliters of Complex Water Samples. ACS Nano, 12 (10). pp. 10281-10290. ISSN 1936-0851. PMCID PMC6202633. doi:10.1021/acsnano.8b05384.

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In this work, we introduce an asymmetric membrane as a simple and robust nanofluidic platform for digital detection of single pathogenic bacteria directly in 10 mL of unprocessed environmental water samples. The asymmetric membrane, consisting of uniform micropores on one side and a high density of vertically aligned nanochannels on the other side, was prepared within 1 min by a facile method. The single membrane covers all the processing steps from sample concentration, purification, and partition to final digital loop-mediated isothermal amplification (LAMP). By simple filtration, bacteria were enriched and partitioned inside the micropores, while inhibitors typically found in the environmental samples (i.e., proteins, heavy metals, and organics) were washed away through the nanochannels. Meanwhile, large particles, indigenous plankton, and positively charged pollutants in the samples were excluded by using a sacrificial membrane stacked on top. After initial filtration, modified LAMP reagents, including NaF and lysozyme, were loaded onto the membrane. Each pore in the asymmetric membrane functioned as an individual nanoreactor for selective, rapid, and efficient isothermal amplification of single bacteria, generating a bright fluorescence for direct counting. Even though high levels of inhibitors were present, absolute quantification of Escherichia coli and Salmonella directly in an unprocessed environmental sample (seawater and pond water) was achieved within 1 h, with sensitivity down to single cell and a dynamic range of 0.3–10000 cells/mL. The simple and low-cost analysis platform described herein has an enormous potential for the detection of pathogens, exosomes, stem cells, and viruses as well as single-cell heterogeneity analysis in environmental, food, and clinical research.

Item Type:Article
Related URLs:
URLURL TypeDescription Information CentralArticle
Lin, Xingyu0000-0002-0950-0736
Huang, Xiao0000-0002-3737-6939
Zhu, Yanzhe0000-0002-2260-1830
Xie, Xing0000-0002-2253-0964
Hoffmann, Michael R.0000-0001-6495-1946
Additional Information:© 2018 American Chemical Society. ACS AuthorChoice - This is an open access article published under a Creative Commons Attribution (CC-BY) License, which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited. Received: July 17, 2018; Accepted: September 13, 2018; Published: September 13, 2018. The authors acknowledge the financial support provided by the Bill and Melinda Gates Foundation (Grant No. OPP1111252). The authors declare no competing financial interest.
Funding AgencyGrant Number
Bill and Melinda Gates FoundationOPP1111252
Subject Keywords:asymmetric membrane; nanofluidics; pathogen detection; digital LAMP; single-molecule counting
Issue or Number:10
PubMed Central ID:PMC6202633
Record Number:CaltechAUTHORS:20180913-133202881
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Official Citation:Asymmetric Membrane for Digital Detection of Single Bacteria in Milliliters of Complex Water Samples. Xingyu Lin, Xiao Huang, Yanzhe Zhu, Katharina Urmann, Xing Xie, and Michael R. Hoffmann. ACS Nano 2018 12 (10), 10281-10290. DOI: 10.1021/acsnano.8b05384
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:89613
Deposited By: George Porter
Deposited On:13 Sep 2018 20:46
Last Modified:07 Mar 2022 18:54

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