{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,1]],"date-time":"2026-02-01T08:53:00Z","timestamp":1769935980417,"version":"3.49.0"},"reference-count":38,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2024,4,30]],"date-time":"2024-04-30T00:00:00Z","timestamp":1714435200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/2.zoppoz.workers.dev:443\/https\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"US Army Office of Research","award":["W911NF2210044"],"award-info":[{"award-number":["W911NF2210044"]}]},{"name":"US Army Office of Research","award":["1711463"],"award-info":[{"award-number":["1711463"]}]},{"name":"US Army Office of Research","award":["DE-AC02-06CH11357"],"award-info":[{"award-number":["DE-AC02-06CH11357"]}]},{"name":"NSF","award":["W911NF2210044"],"award-info":[{"award-number":["W911NF2210044"]}]},{"name":"NSF","award":["1711463"],"award-info":[{"award-number":["1711463"]}]},{"name":"NSF","award":["DE-AC02-06CH11357"],"award-info":[{"award-number":["DE-AC02-06CH11357"]}]},{"name":"U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences","award":["W911NF2210044"],"award-info":[{"award-number":["W911NF2210044"]}]},{"name":"U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences","award":["1711463"],"award-info":[{"award-number":["1711463"]}]},{"name":"U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences","award":["DE-AC02-06CH11357"],"award-info":[{"award-number":["DE-AC02-06CH11357"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Label-free measurement and analysis of single bacterial cells are essential for food safety monitoring and microbial disease diagnosis. We report a microwave flow cytometric sensor with a microstrip sensing device with reduced channel height for bacterial cell measurement. Escherichia coli B and Escherichia coli K-12 were measured with the sensor at frequencies between 500 MHz and 8 GHz. The results show microwave properties of E. coli cells are frequency-dependent. A LightGBM model was developed to classify cell types at a high accuracy of 0.96 at 1 GHz. Thus, the sensor provides a promising label-free method to rapidly detect and differentiate bacterial cells. Nevertheless, the method needs to be further developed by comprehensively measuring different types of cells and demonstrating accurate cell classification with improved machine-learning techniques.<\/jats:p>","DOI":"10.3390\/s24092870","type":"journal-article","created":{"date-parts":[[2024,5,3]],"date-time":"2024-05-03T08:02:22Z","timestamp":1714723342000},"page":"2870","update-policy":"https:\/\/2.zoppoz.workers.dev:443\/https\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Microwave Flow Cytometric Detection and Differentiation of Escherichia coli"],"prefix":"10.3390","volume":"24","author":[{"given":"Neelima","family":"Dahal","sequence":"first","affiliation":[{"name":"Holcombe Department of Electrical and Computer Engineering, Clemson University, Clemson, SC 29634, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Caroline","family":"Peak","sequence":"additional","affiliation":[{"name":"Department of Bioengineering, Clemson University, Clemson, SC 29634, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/2.zoppoz.workers.dev:443\/https\/orcid.org\/0000-0002-0711-0347","authenticated-orcid":false,"given":"Carl","family":"Ehrett","sequence":"additional","affiliation":[{"name":"Watt Family Innovation Center, Clemson University, Clemson, SC 29634, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jeffrey","family":"Osterberg","sequence":"additional","affiliation":[{"name":"Holcombe Department of Electrical and Computer Engineering, Clemson University, Clemson, SC 29634, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Min","family":"Cao","sequence":"additional","affiliation":[{"name":"Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/2.zoppoz.workers.dev:443\/https\/orcid.org\/0000-0002-6343-942X","authenticated-orcid":false,"given":"Ralu","family":"Divan","sequence":"additional","affiliation":[{"name":"Argonne National Laboratory, Chicago, IL 60439, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Pingshan","family":"Wang","sequence":"additional","affiliation":[{"name":"Holcombe Department of Electrical and Computer Engineering, Clemson University, Clemson, SC 29634, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,4,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"529","DOI":"10.3934\/microbiol.2017.3.529","article-title":"Foodborne pathogens","volume":"3","author":"Bintsis","year":"2017","journal-title":"AIMS Microbiol."},{"key":"ref_2","unstructured":"(2023, August 13). CDC\u2014What is Sepsis?, Available online: https:\/\/2.zoppoz.workers.dev:443\/https\/www.cdc.gov\/sepsis\/what-is-sepsis.html."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"4","DOI":"10.4161\/viru.27372","article-title":"Epidemiology of severe sepsis","volume":"5","author":"Mayr","year":"2014","journal-title":"Virulence"},{"key":"ref_4","unstructured":"(2018). Burden of Foodborne Illness: Findings, Centers for Disease Control and Prevention."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"7","DOI":"10.3201\/eid1701.P11101","article-title":"Foodborne Illness Acquired in the United States-Major Pathogens","volume":"17","author":"Scallan","year":"2011","journal-title":"Emerg. Infect Dis."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"3713","DOI":"10.3390\/s90503713","article-title":"Nucleic acid-based detection of bacterial pathogens using integrated microfluidic platform systems","volume":"9","author":"Lui","year":"2009","journal-title":"Sensors"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1016\/j.bios.2018.10.006","article-title":"A microfluidic colorimetric biosensor for rapid detection O157:H7 Escherichia coli O157:H7 using gold nanoparticle aggregation and smart phone imaging","volume":"124","author":"Zheng","year":"2019","journal-title":"Biosens. Bioelectron."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Nakar, A., Pistiki, A., Ryabchykov, O., Bocklitz, T., R\u00f6sch, P., and Popp, J. (2022). Label-free differentiation of clinical E. coli and Klebsiella isolates with Raman spectroscopy. J. Biophotonics, 15.","DOI":"10.1002\/jbio.202200005"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Wu, W., Nguyen, B.T.T., Liu, P.Y., Cai, G., Feng, S., Shi, Y., Zhang, B., Hong, Y., Yu, R., and Zhou, X. (2022). Single Escherichia coli bacteria detection using a chemiluminescence digital microwell array chip. Biosens. Bioelectron., 215.","DOI":"10.1016\/j.bios.2022.114594"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1016\/j.bios.2018.03.014","article-title":"Rapid detection of single E. coli bacteria using a graphene-based field-effect transistor device","volume":"110","author":"Thakur","year":"2018","journal-title":"Biosens. Bioelectron."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"423","DOI":"10.1021\/acssensors.9b02119","article-title":"High-Speed Single-Cell Dielectric Spectroscopy","volume":"5","author":"Spencer","year":"2020","journal-title":"ACS Sens."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2865","DOI":"10.1021\/acs.analchem.1c04739","article-title":"Modified Red Blood Cells as Multimodal Standards for Benchmarking Single-Cell Cytometry and Separation Based on Electrical Physiology","volume":"94","author":"Salahi","year":"2022","journal-title":"Anal. Chem."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2881","DOI":"10.1039\/b910053a","article-title":"Leukocyte analysis and differentiation using high speed microfluidic single cell impedance cytometry","volume":"9","author":"Holmes","year":"2009","journal-title":"Lab Chip"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1039\/D0LC00840K","article-title":"Single-cell microfluidic impedance cytometry: From raw signals to cell phenotypes using data analytics","volume":"21","author":"Honrado","year":"2021","journal-title":"Lab Chip"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"3665","DOI":"10.1039\/D0LC00616E","article-title":"Positional dependence of particles and cells in microfluidic electrical impedance flow cytometry: Origin, challenges and opportunities","volume":"20","author":"Daguerre","year":"2020","journal-title":"Lab Chip"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"6374","DOI":"10.1021\/acs.analchem.2c05822","article-title":"Floating-Electrode-Enabled Impedance Cytometry for Single-Cell 3D Localization","volume":"95","author":"Fang","year":"2023","journal-title":"Anal. Chem."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Bertelsen, C.V., Franco, J.C., Skands, G.E., Dimaki, M., and Svendsen, W.E. (2020). Investigating the Use of Impedance Flow Cytometry for Classifying the Viability State of E. coli. Sensors, 20.","DOI":"10.3390\/s20216339"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1875","DOI":"10.1109\/TMTT.2020.3048176","article-title":"Microwave sensing of yeast cell species and viability","volume":"69","author":"Osterberg","year":"2021","journal-title":"IEEE Trans. Microw. Theory Techn."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"566","DOI":"10.1109\/JERM.2022.3201698","article-title":"Spectroscopic Analysis of Candida Species, Viability, and Antifungal Drug Effects with a Microwave Flow Cytometer","volume":"6","author":"Dahal","year":"2022","journal-title":"IEEE J. Electromagn. RF Microw. Med. Biol."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Clausen, C.H., Dimaki, M., Bertelsen, C.V., Skands, G.E., Rodriguez-Trujillo, R., Thomsen, J.D., and Svendsen, W.E. (2018). Bacteria Detection and Differentiation Using Impedance Flow Cytometry. Sensors, 18.","DOI":"10.3390\/s18103496"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Farasat, M., Aalaei, E., Ronizi, S.K., Bakhshi, A., Mirhosseini, S., Zhang, J., Nguyen, N.-T., and Kashaninejad, N. (2022). Signal-Based Methods in Dielectrophoresis for Cell and Particle Separation. Biosensors, 12.","DOI":"10.20944\/preprints202206.0261.v1"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"5198","DOI":"10.1039\/C5AN00796H","article-title":"A dielectrophoretic method of discrimination between normal oral epithelium, and oral and oropharyngeal cancer in a clinical setting","volume":"140","author":"Graham","year":"2015","journal-title":"Analyst"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"3627","DOI":"10.1021\/acs.analchem.3c05755","article-title":"Bipolar Electrode-based Sheath-Less Focusing and Continuous Acoustic Sorting of Particles and Cells in an Integrated Microfluidic Device","volume":"96","author":"Wu","year":"2024","journal-title":"Anal. Chem."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1981","DOI":"10.1039\/D0LC00175A","article-title":"Acoustic separation of living and dead cells using high density medium","volume":"20","author":"Olofsson","year":"2020","journal-title":"Lab Chip"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"116932","DOI":"10.1016\/j.trac.2023.116932","article-title":"Recent advances in droplet microfluidics for single-cell analysis","volume":"159","author":"Zhenqui","year":"2023","journal-title":"Trend Anal. Chem."},{"key":"ref_26","first-page":"991","article-title":"Multi-frequency DEP cytometer employing a microwave sensor for dielectric analysis of single cells","volume":"64","author":"Afshar","year":"2016","journal-title":"IEEE Trans. Microw. Theory"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"3512","DOI":"10.1109\/TMTT.2017.2653776","article-title":"Microwave monitoring of single cell monocytes subjected to electroporation","volume":"65","author":"Tamra","year":"2017","journal-title":"IEEE Trans. Microw. Theory"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"2223","DOI":"10.1109\/TBME.2018.2885781","article-title":"Correlation between optical fluorescence and microwave transmission during single-cell electroporation","volume":"66","author":"Li","year":"2018","journal-title":"IEEE Trans. Bio-Med. Eng."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1614","DOI":"10.1016\/j.snb.2017.08.179","article-title":"Differentiation of live and heat-killed E. coli by microwave impedance spectroscopy","volume":"255","author":"Li","year":"2018","journal-title":"Sens. Actuators B Chem."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Shahri, A.A., Omidvar, A.H., Rehder, G.P., and Serrano, A.L.C. (2022). A Microwave-Based Microfluidic Cell Detecting Biosensor for Biological Quantification Using the Metallic Nanowire-Filled Membrane Technology. Sensors, 22.","DOI":"10.3390\/s22093265"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"497","DOI":"10.1038\/s41598-017-18806-9","article-title":"Microwave measurement of giant unilamellar vesicles in aqueous solution","volume":"8","author":"Cui","year":"2018","journal-title":"Sci. Rep."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"6517","DOI":"10.1109\/JSEN.2023.3250401","article-title":"High-Resolution Dielectric Characterization of Single Cells and Microparticles Using Integrated Microfluidic Microwave Sensors","volume":"23","author":"Secme","year":"2023","journal-title":"IEEE Sens. J."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Wang, Z., Raval, Y., Tzeng, T.R., Booth, B., Flaherty, B., Peterson, D., Moore, J., Rosenmann, D., Divan, R., and Yu, G. (2016, January 24\u201327). Time domain detection and differentiation of single particles and cells with a radio frequency interferometer. Proceedings of the 2016 IEEE Topical Conference on Biomedical Wireless Technologies, Networks, and Sensing Systems (BioWireleSS), Austin, TX, USA.","DOI":"10.1109\/BIOWIRELESS.2016.7445567"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1049\/iet-nbt:20070019","article-title":"Analytical electric field and sensitivity analysis for two microfluidic impedance cytometer designs","volume":"1","author":"Sun","year":"2007","journal-title":"IET Nanobiotechnol."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Akiba, T., Sano, S., Yanase, T., Ohta, T., and Koyama, M. (2019, January 4\u20138). Optuna: A next-generation hyperparameter optimization framework. Proceedings of the 25th ACM SIGKDD International Conference on Knowledge Discovery & Data Mining, Anchorage, AK, USA.","DOI":"10.1145\/3292500.3330701"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"74","DOI":"10.5617\/jeb.401","article-title":"401Marking 100 years since Rudolf H\u00f6ber\u2019s discovery of the insulating envelope surrounding cells and of the \u03b2-dispersion exhibited by tissue","volume":"3","author":"Pethig","year":"2012","journal-title":"J. Electr. Bioimpedance"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"3754","DOI":"10.1063\/1.1649455","article-title":"Low-frequency, low-field dielectric spectroscopy of living cell suspensions","volume":"95","author":"Prodan","year":"2004","journal-title":"J. Appl. Phys."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"265","DOI":"10.1038\/178265b0","article-title":"Electrical properties of the plasma membrane of erythrocytes at low frequencies","volume":"178","author":"Bothwell","year":"1956","journal-title":"Nature"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/2.zoppoz.workers.dev:443\/https\/www.mdpi.com\/1424-8220\/24\/9\/2870\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T14:37:28Z","timestamp":1760107048000},"score":1,"resource":{"primary":{"URL":"https:\/\/2.zoppoz.workers.dev:443\/https\/www.mdpi.com\/1424-8220\/24\/9\/2870"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,4,30]]},"references-count":38,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2024,5]]}},"alternative-id":["s24092870"],"URL":"https:\/\/2.zoppoz.workers.dev:443\/https\/doi.org\/10.3390\/s24092870","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,4,30]]}}}