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Myers DR, Weiss A, Rollins MR, Lam WA. Towards remote assessment and screening of acute abdominal pain using only a smartphone with native accelerometers. Sci Rep 2017; 7:12750. [PMID: 28986551 PMCID: PMC5630621 DOI: 10.1038/s41598-017-13076-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 09/18/2017] [Indexed: 01/28/2023] Open
Abstract
Smartphone-based telehealth holds the promise of shifting healthcare from the clinic to the home, but the inability for clinicians to conduct remote palpation, or touching, a key component of the physical exam, remains a major limitation. This is exemplified in the assessment of acute abdominal pain, in which a physician's palpation determines if a patient's pain is life-threatening requiring emergency intervention/surgery or due to some less-urgent cause. In a step towards virtual physical examinations, we developed and report for the first time a "touch-capable" mHealth technology that enables a patient's own hands to serve as remote surrogates for the physician's in the screening of acute abdominal pain. Leveraging only a smartphone with its native accelerometers, our system guides a patient through an exact probing motion that precisely matches the palpation motion set by the physician. An integrated feedback algorithm, with 95% sensitivity and specificity, enabled 81% of tested patients to match a physician abdominal palpation curve with <20% error after 6 attempts. Overall, this work addresses a key issue in telehealth that will vastly improve its capabilities and adoption worldwide.
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Affiliation(s)
- David R Myers
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA, 30332, USA.,Department of Pediatrics, Division of Pediatric Hematology/Oncology, Aflac Cancer Center and Blood Disorders Service of Children's Healthcare of Atlanta, Emory University School of Medicine, Atlanta, GA, 30423, USA.,Winship Cancer Institute of Emory University, Atlanta, GA, 30423, USA.,Parker H. Petit Institute of Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Alexander Weiss
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA, 30332, USA
| | - Margo R Rollins
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA, 30332, USA.,Department of Pediatrics, Division of Pediatric Hematology/Oncology, Aflac Cancer Center and Blood Disorders Service of Children's Healthcare of Atlanta, Emory University School of Medicine, Atlanta, GA, 30423, USA.,Winship Cancer Institute of Emory University, Atlanta, GA, 30423, USA.,Parker H. Petit Institute of Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Wilbur A Lam
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA, 30332, USA. .,Department of Pediatrics, Division of Pediatric Hematology/Oncology, Aflac Cancer Center and Blood Disorders Service of Children's Healthcare of Atlanta, Emory University School of Medicine, Atlanta, GA, 30423, USA. .,Winship Cancer Institute of Emory University, Atlanta, GA, 30423, USA. .,Parker H. Petit Institute of Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
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Andjelković U, Šrajer Gajdošik M, Gašo-Sokač D, Martinović T, Josić D. Foodomics and Food Safety: Where We Are. Food Technol Biotechnol 2017; 55:290-307. [PMID: 29089845 PMCID: PMC5654429 DOI: 10.17113/ftb.55.03.17.5044] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 05/31/2017] [Indexed: 12/21/2022] Open
Abstract
The power of foodomics as a discipline that is now broadly used for quality assurance of food products and adulteration identification, as well as for determining the safety of food, is presented. Concerning sample preparation and application, maintenance of highly sophisticated instruments for both high-performance and high-throughput techniques, and analysis and data interpretation, special attention has to be paid to the development of skilled analysts. The obtained data shall be integrated under a strong bioinformatics environment. Modern mass spectrometry is an extremely powerful analytical tool since it can provide direct qualitative and quantitative information about a molecule of interest from only a minute amount of sample. Quality of this information is influenced by the sample preparation procedure, the type of mass spectrometer used and the analyst's skills. Technical advances are bringing new instruments of increased sensitivity, resolution and speed to the market. Other methods presented here give additional information and can be used as complementary tools to mass spectrometry or for validation of obtained results. Genomics and transcriptomics, as well as affinity-based methods, still have a broad use in food analysis. Serious drawbacks of some of them, especially the affinity-based methods, are the cross-reactivity between similar molecules and the influence of complex food matrices. However, these techniques can be used for pre-screening in order to reduce the large number of samples. Great progress has been made in the application of bioinformatics in foodomics. These developments enabled processing of large amounts of generated data for both identification and quantification, and for corresponding modeling.
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Affiliation(s)
- Uroš Andjelković
- Department of Biotechnology, University of Rijeka, Radmile Matejčić 2, HR-51000 Rijeka, Croatia
- Department of Chemistry, Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Njegoševa 12, RS-11000 Belgrade, Serbia
| | - Martina Šrajer Gajdošik
- Department of Chemistry, J. J. Strossmayer University of Osijek, Cara Hadrijana 8/A, HR-31000 Osijek, Croatia
| | - Dajana Gašo-Sokač
- Faculty of Food Technology, J. J. Strossmayer University of Osijek, Franje Kuhača 20, HR-31000 Osijek, Croatia
| | - Tamara Martinović
- Department of Biotechnology, University of Rijeka, Radmile Matejčić 2, HR-51000 Rijeka, Croatia
| | - Djuro Josić
- Department of Biotechnology, University of Rijeka, Radmile Matejčić 2, HR-51000 Rijeka, Croatia
- Warren Alpert Medical School, Brown University, 222 Richmond St, Providence, RI 02903, USA
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3
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Yang X, Wei D, Yan S, Liu Y, Yu S, Zhang M, Yang Z, Zhu X, Huang Q, Cui HL, Fu W. Rapid and label-free detection and assessment of bacteria by terahertz time-domain spectroscopy. JOURNAL OF BIOPHOTONICS 2016; 9:1050-1058. [PMID: 26890249 DOI: 10.1002/jbio.201500270] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 12/08/2015] [Accepted: 01/29/2016] [Indexed: 05/27/2023]
Abstract
Here we demonstrated the potential and applicability of terahertz (THz) spectroscopy to detect four commonly found bacteria in the infectious diseases. Besides the different spectral characteristics between bacterial species, THz absorption differences for living bacteria, dead bacteria and bacterial powder of the same species were also investigated. Our results revealed that small differences in water contents between bacterial cells account for distinct discrepancies of the absorption coefficients, which can be used for bacterial species identification. Furthermore, living and dead bacteria showed different absorption coefficients as a result of their different hydration levels, suggesting that THz spectroscopy can be used to rapidly assess the living state of bacteria under test. Our results clearly demonstrated the ability of THz spectroscopy for time-saving and label-free detection of bacteria with minimal sample preparation, potentially to be utilized for point-of-care tests in the near future. Schematic representation of bacterial detection by THz spectroscopy. Different bacteria have distinctive absorption coefficients as a result of their different water contents.
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Affiliation(s)
- Xiang Yang
- Department of Laboratory Medicine, Southwest Hospital, Third Military Medical University, Chongqing, 400038, China
| | - Dongshan Wei
- Chongqing Key Laboratory of Multi-scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China
| | - Shihan Yan
- Chongqing Key Laboratory of Multi-scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China
| | - Yueping Liu
- Department of Laboratory Medicine, Southwest Hospital, Third Military Medical University, Chongqing, 400038, China
| | - Shu Yu
- Department of Laboratory Medicine, Southwest Hospital, Third Military Medical University, Chongqing, 400038, China
| | - Mingkun Zhang
- Chongqing Key Laboratory of Multi-scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China
| | - Zhongbo Yang
- Chongqing Key Laboratory of Multi-scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China
| | - Xiaoyan Zhu
- Department of Laboratory Medicine, Southwest Hospital, Third Military Medical University, Chongqing, 400038, China
| | - Qing Huang
- Department of Laboratory Medicine, Southwest Hospital, Third Military Medical University, Chongqing, 400038, China
| | - Hong-Liang Cui
- Chongqing Key Laboratory of Multi-scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China.
- College of Instrumentation Science and Electrical Engineering, Jilin University, Changchun, Jilin, 130061, China.
| | - Weiling Fu
- Department of Laboratory Medicine, Southwest Hospital, Third Military Medical University, Chongqing, 400038, China.
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Jamshaid T, Neto ETT, Eissa MM, Zine N, Kunita MH, El-Salhi AE, Elaissari A. Magnetic particles: From preparation to lab-on-a-chip, biosensors, microsystems and microfluidics applications. Trends Analyt Chem 2016. [DOI: 10.1016/j.trac.2015.10.022] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Demirkol DO, Timur S. A sandwich-type assay based on quantum dot/aptamer bioconjugates for analysis ofE. ColiO157:H7 in microtiter plate format. INT J POLYM MATER PO 2015. [DOI: 10.1080/00914037.2015.1074906] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Kersaudy-Kerhoas M, Sollier E. Micro-scale blood plasma separation: from acoustophoresis to egg-beaters. LAB ON A CHIP 2013; 13:3323-46. [PMID: 23824514 DOI: 10.1039/c3lc50432h] [Citation(s) in RCA: 124] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Plasma is a rich mine of various biomarkers including proteins, metabolites and circulating nucleic acids. The diagnostic and therapeutic potential of these analytes has been quite recently uncovered, and the number of plasma biomarkers will still be growing in the coming years. A significant part of the blood plasma preparation is still handled manually, off-chip, via centrifugation or filtration. These batch methods have variable waiting times, and are often performed under non-reproducible conditions that may impair the collection of analytes of interest, with variable degradation. The development of miniaturised modules capable of automated and reproducible blood plasma separation would aid in the translation of lab-on-a-chip devices to the clinical market. Here we propose a systematic review of major plasma analytes and target applications, alongside existing solutions for micro-scale blood plasma extraction, focusing on the approaches that have been biologically validated for specific applications.
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Affiliation(s)
- Maïwenn Kersaudy-Kerhoas
- Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University, Edinburgh Campus, Edinburgh EH14 4AS, United Kingdom.
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7
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David S, Polonschii C, Gheorghiu M, Bratu D, Dobre A, Gheorghiu E. Assessment of pathogenic bacteria using periodic actuation. LAB ON A CHIP 2013; 13:3192-3198. [PMID: 23807196 DOI: 10.1039/c3lc50411e] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A new analytical platform for the assessment of pathogenic bacteria is presented. It is based on a robust technology which is able to amplify the signal to noise ratio providing fast and sensitive detection of target pathogenic bacteria. The system uses a custom made AC electrical impedance analyser to measure, using a lab on a chip platform, the oscillations of magnetically labelled analytes when applying a periodic magnetic field. The concentration of pathogenic Escherichia coli O157:H7 chosen as bacterial model was determined based on the amplitude of the electrical impedance oscillations at a selected AC frequency. The analytical platform provides a limit of detection of 10(2) cells ml(-1), has a fast analysis time, and is amenable for the detection of other target cells. The system has simple design suitable for portability and automated operation.
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Affiliation(s)
- Sorin David
- International Centre of Biodynamics, Intrarea Portocalelor Nr. 1B, Bucharest, Romania
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Factors determining the occurrence of submicroscopic malaria infections and their relevance for control. Nat Commun 2013; 3:1237. [PMID: 23212366 PMCID: PMC3535331 DOI: 10.1038/ncomms2241] [Citation(s) in RCA: 448] [Impact Index Per Article: 40.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 10/31/2012] [Indexed: 01/05/2023] Open
Abstract
Malaria parasite prevalence in endemic populations is an essential indicator for monitoring the progress of malaria control, and has traditionally been assessed by microscopy. However, surveys increasingly use sensitive molecular methods that detect higher numbers of infected individuals, questioning our understanding of the true infection burden and resources required to reduce it. Here we analyse a series of data sets to characterize the distribution and epidemiological factors associated with low-density, submicroscopic infections. We show that submicroscopic parasite carriage is common in adults, in low-endemic settings and in chronic infections. We find a strong, non-linear relationship between microscopy and PCR prevalence in population surveys (n=106), and provide a tool to relate these measures. When transmission reaches very low levels, submicroscopic carriers are estimated to be the source of 20–50% of all human-to-mosquito transmissions. Our findings challenge the idea that individuals with little previous malaria exposure have insufficient immunity to control parasitaemia and suggest a role for molecular screening. Malaria can persist at levels that escape detection by standard microscopy, but can be detected by PCR. Okell et al. now show that rates of submicroscopic infection can be predicted using more widely available microscopy data, and are most epidemiologically significant in areas with low malaria transmission.
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Affiliation(s)
- Ravi Komatireddy
- Scripps Translational Science Institute
- The Scripps Research Institute, and
- Scripps Health, La Jolla, CA
| | - Eric J Topol
- Scripps Translational Science Institute
- The Scripps Research Institute, and
- Scripps Health, La Jolla, CA
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Miniaturized nucleic acid amplification systems for rapid and point-of-care diagnostics: A review. Anal Chim Acta 2012; 733:1-15. [DOI: 10.1016/j.aca.2012.04.031] [Citation(s) in RCA: 141] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2011] [Revised: 04/10/2012] [Accepted: 04/24/2012] [Indexed: 12/19/2022]
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11
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Gubala V, Harris LF, Ricco AJ, Tan MX, Williams DE. Point of Care Diagnostics: Status and Future. Anal Chem 2011; 84:487-515. [DOI: 10.1021/ac2030199] [Citation(s) in RCA: 832] [Impact Index Per Article: 64.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Vladimir Gubala
- Biomedical Diagnostics Institute, Dublin City University, Dublin 9, Ireland
| | - Leanne F. Harris
- Biomedical Diagnostics Institute, Dublin City University, Dublin 9, Ireland
| | - Antonio J. Ricco
- Biomedical Diagnostics Institute, Dublin City University, Dublin 9, Ireland
| | - Ming X. Tan
- Biomedical Diagnostics Institute, Dublin City University, Dublin 9, Ireland
| | - David E. Williams
- Biomedical Diagnostics Institute, Dublin City University, Dublin 9, Ireland
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12
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Giraud G, Pethig R, Schulze H, Henihan G, Terry JG, Menachery A, Ciani I, Corrigan D, Campbell CJ, Mount AR, Ghazal P, Walton AJ, Crain J, Bachmann TT. Dielectrophoretic manipulation of ribosomal RNA. BIOMICROFLUIDICS 2011; 5:24116. [PMID: 21799722 PMCID: PMC3145241 DOI: 10.1063/1.3604395] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Accepted: 06/06/2011] [Indexed: 05/13/2023]
Abstract
The manipulation of ribosomal RNA (rRNA) extracted from E. coli cells by dielectrophoresis (DEP) has been demonstrated over the range of 3 kHz-50 MHz using interdigitated microelectrodes. Quantitative measurement using total internal reflection fluorescence microscopy of the time dependent collection indicated a positive DEP response characterized by a plateau between 3 kHz and 1 MHz followed by a decrease in response at higher frequencies. Negative DEP was observed above 9 MHz. The positive DEP response below 1 MHz is described by the Clausius-Mossotti model and corresponds to an induced dipole moment of 3300 D with a polarizability of 7.8×10(-32) F m(2). The negative DEP response above 9 MHz indicates that the rRNA molecules exhibit a net moment of -250 D, to give an effective permittivity value of 78.5 ε(0), close to that of the aqueous suspending medium, and a relatively small surface conductance value of ∼0.1 nS. This suggests that our rRNA samples have a fairly open structure accessible to the surrounding water molecules, with counterions strongly bound to the charged phosphate groups in the rRNA backbone. These results are the first demonstration of DEP for fast capture and release of rRNA units, opening new opportunities for rRNA-based biosensing devices.
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13
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Schulze H, Ross AJ, Ember SWJ, Luby J, Khondoker M, Giraud G, Ciani I, Tlili C, Papale D, Terry JG, Mount AR, Walton AJ, Crain J, Ghazal P, Bachmann TT, Campbell CJ. Peptide-tags for enhanced DNA microarray performance. Faraday Discuss 2011; 149:201-10; discussion 227-45. [PMID: 21413182 DOI: 10.1039/c005491g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
DNA microarrays are powerful tools for gene expression analysis and genotyping studies in research and diagnostic applications. A high sensitivity and short time-to-result are prerequisites for their practical application in the clinic. The hybridization efficiency of DNA microarrays depends on the probe density and the probe orientation and thus their accessibility for target molecules. In order to find an optimal probe immobilization procedure a set of different oligonucleotide modifications was tested on epoxy silane functionalized glass slides. It was found that histidine-tagged oligonucleotides resulted in the highest amount of bound probe and by far the best hybridization efficiencies. The detection limit obtained with histidine-tagged probes was up to two orders of magnitude lower compared to commonly used probe modifications. In order to further investigate the binding mechanism of histidine-tags towards functionalized glass substrates a set of different peptide-tags with and without free terminal amino-groups and with different amino acid compositions was tested. The results indicate an impact of the terminal amino group on the covalent surface binding and of aromatic amino acid residues on the enhanced hybridisation efficiency.
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Affiliation(s)
- Holger Schulze
- Division of Pathway Medicine, College of Medicine and Veterinary Medicine, The University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, Scotland.
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Biosensor diagnosis of urinary tract infections: a path to better treatment? Trends Pharmacol Sci 2011; 32:330-6. [PMID: 21458868 DOI: 10.1016/j.tips.2011.03.001] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Revised: 02/28/2011] [Accepted: 03/01/2011] [Indexed: 02/08/2023]
Abstract
Urinary tract infection (UTI) is among the most common bacterial infections and poses a significant healthcare burden. The standard culture-based diagnosis of UTI has a typical delay of two to three days. In the absence of definitive microbiological diagnosis at the point of care, physicians frequently initiate empirical broad-spectrum antibiotic treatment, and this has contributed to the emergence of resistant pathogens. Biosensors are emerging as a powerful diagnostic platform for infectious diseases. Paralleling how blood glucose sensors revolutionized the management of diabetes, and how pregnancy tests are now conducted in the home, biosensors are poised to improve UTI diagnosis significantly. Biosensors are amenable to integration with microfluidic technology for point-of-care (POC) applications. This review focuses on promising biosensor technology for UTI diagnosis, including pathogen identification and antimicrobial susceptibility testing, and hurdles to be surpassed in the translation of biosensor technology from bench to bedside.
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Donhauser SC, Niessner R, Seidel M. Sensitive Quantification of Escherichia coli O157:H7, Salmonella enterica, and Campylobacter jejuni by Combining Stopped Polymerase Chain Reaction with Chemiluminescence Flow-Through DNA Microarray Analysis. Anal Chem 2011; 83:3153-60. [DOI: 10.1021/ac2002214] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Simon Christian Donhauser
- Chair for Analytical Chemistry and Institute of Hydrochemistry, Technische Universität München, Marchioninistrasse 17, D-81377 München, Germany
| | - Reinhard Niessner
- Chair for Analytical Chemistry and Institute of Hydrochemistry, Technische Universität München, Marchioninistrasse 17, D-81377 München, Germany
| | - Michael Seidel
- Chair for Analytical Chemistry and Institute of Hydrochemistry, Technische Universität München, Marchioninistrasse 17, D-81377 München, Germany
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Focke M, Kosse D, Müller C, Reinecke H, Zengerle R, von Stetten F. Lab-on-a-Foil: microfluidics on thin and flexible films. LAB ON A CHIP 2010; 10:1365-86. [PMID: 20369211 DOI: 10.1039/c001195a] [Citation(s) in RCA: 118] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
This critical review is motivated by an increasing interest of the microfluidics community in developing complete Lab-on-a-Chip solutions based on thin and flexible films (Lab-on-a-Foil). Those implementations benefit from a broad range of fabrication methods that are partly adopted from well-established macroscale processes or are completely new and promising. In addition, thin and flexible foils enable various features like low thermal resistance for efficient thermocycling or integration of easily deformable chambers paving the way for new means of on-chip reagent storage or fluid transport. From an economical perspective, Lab-on-a-Foil systems are characterised by low material consumption and often low-cost materials which are attractive for cost-effective high-volume fabrication of self-contained disposable chips. The first part of this review focuses on available materials, fabrication processes and approaches for integration of microfluidic functions including liquid control and transport as well as storage and release of reagents. In the second part, an analysis of the state of Lab-on-a-Foil applications is provided with a special focus on nucleic acid analysis, immunoassays, cell-based assays and home care testing. We conclude that the Lab-on-a-Foil approach is very versatile and significantly expands the toolbox for the development of Lab-on-a-Chip solutions.
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Affiliation(s)
- Maximilian Focke
- Laboratory for MEMS Applications, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Koehler-Allee 106, 79110 Freiburg, Germany
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Mak AC, Osterfeld SJ, Yu H, Wang SX, Davis RW, Jejelowo OA, Pourmand N. Sensitive giant magnetoresistive-based immunoassay for multiplex mycotoxin detection. Biosens Bioelectron 2009; 25:1635-9. [PMID: 20047828 DOI: 10.1016/j.bios.2009.11.028] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Revised: 11/26/2009] [Accepted: 11/27/2009] [Indexed: 11/15/2022]
Abstract
Rapid and multiplexed measurement is vital in the detection of food-borne pathogens. While highly specific and sensitive, traditional immunochemical assays such as enzyme-linked immunosorbent assays (ELISAs) often require expensive read-out equipment (e.g. fluorescent labels) and lack the capability of multiplex detection. By combining the superior specificity of immunoassays with the sensitivity and simplicity of magnetic detection, we have developed a novel multiplex magnetic nanotag-based detection platform for mycotoxins that functions on a sub-picomolar concentration level. Unlike fluorescent labels, magnetic nanotags (MNTs) can be detected with inexpensive giant magnetoresistive (GMR) sensors such as spin-valve sensors. In the system presented here, each spin-valve sensor has an active area of 90 microm x 90 microm, arranged in an 8 x 8 array. Sample is added to the antibody-immobilized sensor array prior to the addition of the biotinylated detection antibody. The sensor response is recorded in real time upon the addition of streptavidin-linked MNTs on the chip. Here we demonstrate the simultaneous detection of multiple mycotoxins (aflatoxins B(1), zearalenone and HT-2) and show that a detection limit of 50 pg/mL can be achieved.
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Affiliation(s)
- Andy C Mak
- Stanford Genome Technology Center, Stanford University, 855 California Ave, Palo Alto, CA 94304, USA
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