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Special Issue "Sensors for Toxic and Pathogen Detection"

A special issue of Sensors (ISSN 1424-8220). This special issue belongs to the section "Biosensors".

Deadline for manuscript submissions: closed (31 July 2017)

Special Issue Editors

Guest Editor
Prof. Dr. Jean-Louis Marty

BAE (Biosensor Analysis Environment), Université de Perpignan Via Domitia, 52 avenue Paul Alduy, 66860 Perpignan CEDEX France
Website | E-Mail
Phone: + 33 (0) 4 68 66 22 54
Fax: + 33 (0) 4 68 66 22 23
Interests: electrochemical and optical biosensors; environment and agro food fields; pollutants and toxins; screen printed electrodes; aptamers
Guest Editor
Prof. Silvana Andreescu

Department of Chemistry and Biomolecular Science Clarkson University 8 Clarkson Avenue Potsdam, NY 13699-5810, USA
Website | E-Mail
Interests: field portable sensors for toxins; switchable biomolecular assays; microelectrochemical probes; redox active nanoparticles; environmental and clinical analysis
Guest Editor
Dr. Akhtar Hayat

Interdisciplinary Research Centre in Biomedical Materials (IRCBM) COMSATS Institute of Information Technology, 54000 Lahore, Pakistan
Website | E-Mail
Interests: nanomaterials; aptamer/aptasensor; immuno-assay/sensors; enzyme-assay/sensors; electrochemical/colorimetric/fluorescence sensors/biosensors; medical/food/environmental applications

Special Issue Information

Dear Colleagues,

The monitoring of pathogens and toxins is one of the key issues in understanding and managing hazards to human health and safety. Pathogen contaminants have mild to severe short-term or long term effect and some of them even have deadly effects and lead to widespread havoc. Very strict legislation is implemented in areas such as the food industry, in order to prevent the terrible consequences of pathogen and toxins. Although, there has been a great deal of interest in developing techniques for the monitoring of pathogens, there is still great demand for portable, decentralized and highly robust assays. In this context, biosensors have achieved intense significance because of their capability to resolve a potentially large number of problems and challenges in pathogen contamination. A biosensor is a compact analytical device incorporating a biorecognition element as the sensing element, either integrated within or intimately associated with a physiochemical transducer surface. This Special Issue aims to promote new trends in the area of pathogen detection and recent designs in the field of pathogen and toxins biosensors.

We would like to invite you to participate in this Special Issue by submitting both original research papers and review articles on biosensors for pathogen and toxin detection.

Prof. Jean-Louis Marty
Prof. Silvana Andreescu
Dr Akhtar Hayat
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Sensors is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Biosensors
  • nanosensors
  • portable sensors
  • electrochemical sensors
  • optical assays
  • pathogen and toxin detection
  • food analysis
  • environmental analysis

Published Papers (20 papers)

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Research

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Open AccessArticle Bioelectrochemical Detection of Mycobacterium tuberculosis ESAT-6 in an Antibody-Based Biomicrosystem
Sensors 2017, 17(10), 2178; doi:10.3390/s17102178
Received: 5 August 2017 / Revised: 2 September 2017 / Accepted: 7 September 2017 / Published: 22 September 2017
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Abstract
Bioelectrochemical sensing of Mycobacterium tuberculosis through electro-immunosensors is a promising technique to detect relevant analytes. In general, immunosensors require the formation of organic assemblies by the adsorption of molecular constituents. Moreover, they depend on the correct immobilization of the bio-recognition element in the
[...] Read more.
Bioelectrochemical sensing of Mycobacterium tuberculosis through electro-immunosensors is a promising technique to detect relevant analytes. In general, immunosensors require the formation of organic assemblies by the adsorption of molecular constituents. Moreover, they depend on the correct immobilization of the bio-recognition element in the biosensor. These procedures cannot be easily monitored without the use of invasive methods. In this work, an impedance analysis technique was used, as a non-invasive method, to measure and differentiate the manufacturing stages of the sensors. Biomicrosystems were fabricated through physical vapor deposition (PVD) of 80 nm Au nanolayers on 35 µm copper surfaces. Later, the surface was modified through thiolation methods generating a self-assembled-monolayer (SAM) with 20 mM 4-aminothiophenol (4-ATP) on which a polyclonal antibody (pAb) was covalently attached. Using impedance analysis, every step of the electro-immunosensor fabrication protocol was characterized using 40 independent replicas. Results showed that, compared to the negative controls, distilled water, and 0.5 µg/mL HSA, a maximum variation of 171% between each replica was achieved when compared to samples containing 0.5 µg/mL of ESAT-6 M. tuberculosis immunodominant protein. Therefore, this development validates a non-invasive method to electrically monitor the assembly process of electro-immunosensors and a tool for its further measure for detection of relevant antigens. Full article
(This article belongs to the Special Issue Sensors for Toxic and Pathogen Detection)
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Open AccessArticle Sensitive Genotyping of Foodborne-Associated Human Noroviruses and Hepatitis A Virus Using an Array-Based Platform
Sensors 2017, 17(9), 2157; doi:10.3390/s17092157
Received: 20 July 2017 / Revised: 15 September 2017 / Accepted: 18 September 2017 / Published: 20 September 2017
PDF Full-text (2649 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Human noroviruses (NoV) are the leading cause of human gastroenteritis in populations of all ages and are linked to most of the foodborne outbreaks worldwide. Hepatitis A virus (HAV) is another important foodborne enteric virus and is considered the most common agent causing
[...] Read more.
Human noroviruses (NoV) are the leading cause of human gastroenteritis in populations of all ages and are linked to most of the foodborne outbreaks worldwide. Hepatitis A virus (HAV) is another important foodborne enteric virus and is considered the most common agent causing acute liver disease worldwide. In the present study, a focused, low-density DNA microarray was developed and validated for the simultaneous identification of foodborne-associated genotypes of NoV and HAV. By employing a novel algorithm, capture probes were designed to target variable genomic regions commonly used for typing these foodborne viruses. Validation results showed that probe signals, specific for the tested NoV or HAV genotypes, were on average 200-times or 38-times higher than those detected for non-targeted genotypes, respectively. To improve the analytical sensitivity of this method, a 12-mer oligonucleotide spacer sequence was added to the capture probes and resulted in a detection threshold of less than 10 cRNA transcripts. These findings have indicated that this array-based typing sensor has the accuracy and sensitivity for identifying NoV and HAV genotypic profiles predominantly linked to food poisoning. The implementation of this typing sensor would thus provide highly relevant and valuable information for use in surveillance and outbreak attribution. Full article
(This article belongs to the Special Issue Sensors for Toxic and Pathogen Detection)
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Open AccessArticle Repetitive Immunosensor with a Fiber-Optic Device and Antibody-Coated Magnetic Beads for Semi-Continuous Monitoring of Escherichia coli O157:H7
Sensors 2017, 17(9), 2145; doi:10.3390/s17092145
Received: 31 July 2017 / Revised: 12 September 2017 / Accepted: 15 September 2017 / Published: 19 September 2017
PDF Full-text (7756 KB) | HTML Full-text | XML Full-text
Abstract
A rapid and reproducible fiber-optic immunosensor for Escherichia coli O157:H7 (E. coli O157:H7) was described. The biosensor consisted of a flow cell, an optical fiber with a thin Ni layer, and a PC linked fluorometer. First, the samples with E. coli O157:H7
[...] Read more.
A rapid and reproducible fiber-optic immunosensor for Escherichia coli O157:H7 (E. coli O157:H7) was described. The biosensor consisted of a flow cell, an optical fiber with a thin Ni layer, and a PC linked fluorometer. First, the samples with E. coli O157:H7 were incubated with magnetic beads coated with anti-E. coli O157:H7 antibodies and anti-E. coli O157:H7 antibodies labeled cyanine 5 (Cy5) to make sandwich complexes. Then the Cy5-(E. coli O157:H7)-beads were injected into a flow cell and pulled to the magnetized Ni layer on the optical fiber set in the flow cell. An excitation light (λ = 635 nm) was used to illuminate the optical fiber, and the Cy5 florescent molecules facing the optical fiber were exposed to an evanescent wave from the optical fiber. The 670 nm fluorescent light was measured using a photodiode. Finally, the magnetic intensity of the Ni layer was removed and the Cy5-E. coli O157:H7-beads were washed out for the next immunoassay. E. coli O157:H7, diluted with phosphate buffer (PB), was measured from 1 × 105 to 1 × 107 cells/mL. The total time required for an assay was less than 15 min (except for the pretreatment process) and repeating immunoassay on one optical fiber was made possible. Full article
(This article belongs to the Special Issue Sensors for Toxic and Pathogen Detection)
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Open AccessCommunication Electrical Detection of Pneumococcus through the Nanoparticle Decoration Method
Sensors 2017, 17(9), 2012; doi:10.3390/s17092012
Received: 31 July 2017 / Revised: 19 August 2017 / Accepted: 31 August 2017 / Published: 2 September 2017
PDF Full-text (2045 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
A simple method of nanoparticle decoration can be used in the detection of pneumococcus. After the pneumococcal bacteria were captured by an antibody (pneumococcal C-polysaccharide (PnC) antibody) between the interdigitated electrodes, the gold nanoparticles conjugated with the PnC antibodies were let to bind
[...] Read more.
A simple method of nanoparticle decoration can be used in the detection of pneumococcus. After the pneumococcal bacteria were captured by an antibody (pneumococcal C-polysaccharide (PnC) antibody) between the interdigitated electrodes, the gold nanoparticles conjugated with the PnC antibodies were let to bind onto an outer membrane of the bacteria. Upon successfully dense decoration, the bacteria surface will become conductive owing to the metal nanoparticles, and a distinctive conductance change between the electrodes can be observed. Since this success ratio, or the probability of the conductance change, reflects the concentration of the analyte, a number of repeated measurements can be used in the quantification of the bacteria. In this way, we have successfully detected S. pneumoniae in the range of 10–108 CFU/mL. The limit of detection in this work is lower than that in the commercial detection kit. We hope that the nanoparticle decoration method will play a role in the facile detection of various bacteria. Full article
(This article belongs to the Special Issue Sensors for Toxic and Pathogen Detection)
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Open AccessArticle A Portable Impedance Immunosensing System for Rapid Detection of Salmonella Typhimurium
Sensors 2017, 17(9), 1973; doi:10.3390/s17091973
Received: 20 July 2017 / Revised: 13 August 2017 / Accepted: 22 August 2017 / Published: 28 August 2017
PDF Full-text (2395 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Salmonella Typhimurium is one of the most dangerous foodborne pathogens and poses a significant threat to human health. The objective of this study was to develop a portable impedance immunosensing system for rapid and sensitive detection of S. Typhimurium in poultry. The
[...] Read more.
Salmonella Typhimurium is one of the most dangerous foodborne pathogens and poses a significant threat to human health. The objective of this study was to develop a portable impedance immunosensing system for rapid and sensitive detection of S. Typhimurium in poultry. The developed portable impedance immunosensing system consisted of a gold interdigitated array microelectrode (IDAM), a signal acquisitive interface and a laptop computer with LabVIEW software. The IDAM was first functionalized with 16-Mercaptohexadecanoic acid, and streptavidin was immobilized onto the electrode surface through covalent bonding. Then, biotin-labelled S. Typhimurium-antibody was immobilized onto the IDAM surface. Samples were dropped on the surface of the IDAM and the S. Typhimurium cells in the samples were captured by the antibody on the IDAM. This resulted in impedance changes that were measured and displayed with the LabVIEW software. An equivalent circuit of the immunosensor demonstrated that the largest change in impedance was due to the electron-transfer resistance. The equivalent circuit showed an increase of 35% for the electron-transfer resistance value compared to the negative control. The calibration result indicated that the portable impedance immunosensing system could be used to measure the standard impedance elements, and it had a maximum error of measurement of approximately 13%. For pure culture detection, the system had a linear relationship between the impedance change and the logarithmic value of S. Typhimurium cells ranging from 76 to 7.6 × 106 CFU (colony-forming unit) (50 μL)−1. The immunosensor also had a correlation coefficient of 0.98, and a high specificity for detection of S. Typhimurium cells with a limit of detection (LOD) of 102 CFU (50 μL)−1. The detection time from the moment a sample was introduced to the display of the results was 1 h. To conclude, the portable impedance immunosensing system for detection of S. Typhimurium achieved an LOD that is comparable with commercial electrochemical impedance instruments. The developed impedance immunosensor has advantages in portability, low cost, rapid detection and label-free features showing a great potential for in-field detection of foodborne pathogens. Full article
(This article belongs to the Special Issue Sensors for Toxic and Pathogen Detection)
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Open AccessArticle A Chip for Estrogen Receptor Action: Detection of Biomarkers Released by MCF-7 Cells through Estrogenic and Anti-Estrogenic Effects
Sensors 2017, 17(8), 1760; doi:10.3390/s17081760
Received: 27 June 2017 / Revised: 26 July 2017 / Accepted: 28 July 2017 / Published: 1 August 2017
PDF Full-text (2655 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The fluorescence-based multi-analyte chip platform for the analysis of estrogenic and anti-estrogenic substances is a new in vitro tool for the high throughput screening of environmental samples. In contrast to existing tools, the chip investigates the complex action of xenoestrogens in a human
[...] Read more.
The fluorescence-based multi-analyte chip platform for the analysis of estrogenic and anti-estrogenic substances is a new in vitro tool for the high throughput screening of environmental samples. In contrast to existing tools, the chip investigates the complex action of xenoestrogens in a human cell model by characterizing protein expression. It allows for the quantification of 10 proteins secreted by MCF-7 cells, representing various biological and pathological endpoints of endocrine action and distinguishing between estrogen- and anti-estrogen-dependent secretion of proteins. Distinct protein secretion patterns of the cancer cell line after exposure to known estrogen receptor agonists ß-estradiol, bisphenol A, genistein, and nonylphenol as well as antagonists fulvestrant and tamoxifen demonstrate the potential of the chip. Stimulation of cells with Interleukin-1ß shifts concentrations of low abundant biomarkers towards the working range of the chip. In the non-stimulated cell culture, Matrix Metalloproteinase 9 (MMP-9) and Vascular Endothelial Growth Factor (VEGF) show differences upon treatment with antagonists and agonists of the estrogen receptor. In stimulated MCF-7 cells challenged with receptor agonists secretion of Monocyte Chemoattractant Protein (MCP-1), Interleukin-6 (IL-6), Rantes, and Interleukin-8 (IL-8) significantly decreases. In parallel, the proliferating effect of endocrine-disrupting substances in MCF-7 cells is assessed in a proliferation assay based on resazurin. Using ethanol as a solvent for test substances increases the background of proliferation and secretion experiments, while using dimethyl sulfoxide (DMSO) does not show any adverse effects. The role of the selected biomarkers in different physiological processes such as cell development, reproduction, cancer, and metabolic syndrome makes the chip an excellent tool for either indicating endocrine-disrupting effects in food and environmental samples, or for screening the effect of xenoestrogens on a cellular and molecular level. Full article
(This article belongs to the Special Issue Sensors for Toxic and Pathogen Detection)
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Open AccessArticle Electrochemical Flow-ELISA for Rapid and Sensitive Determination of Microcystin-LR Using Automated Sequential Injection System
Sensors 2017, 17(7), 1639; doi:10.3390/s17071639
Received: 6 June 2017 / Revised: 30 June 2017 / Accepted: 5 July 2017 / Published: 16 July 2017
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Abstract
An amperometric immunoanalysis system based on monoclonal antibodies immobilized on Sepharose beads and packed into a micro-immunocolumn was developed for the quantification of microcystin-LR. Microcystin-LR (MCLR) was used as a reference microcystin variant. Inside the immunocolumn, free microcystins and microcystin-horseradish peroxidase (tracer) were
[...] Read more.
An amperometric immunoanalysis system based on monoclonal antibodies immobilized on Sepharose beads and packed into a micro-immunocolumn was developed for the quantification of microcystin-LR. Microcystin-LR (MCLR) was used as a reference microcystin variant. Inside the immunocolumn, free microcystins and microcystin-horseradish peroxidase (tracer) were sequentially captured by the immobilized antibodies, and the detection was performed electrochemically using Super AquaBlue ELISA substrate 2,2′-azinobis(3-ethylbenzothiazoline-sulfonic acid) (ABTS). The ABTS●+ generated by enzymatic oxidation of ABTS was electrochemically determined at a carbon working electrode by applying a reduction potential set at 0.4 V versus Ag/AgCl reference electrode. The peak current intensity was inversely proportional to the amount of analyte bound to the immunocolumn. The amperometric flow-ELISA system, which was automatically controlled through the CapSenzeTM (Lund, Sweden) computer software, enabled determination of MCLR as low as 0.01 µg/L. The assay time was very short (20 min for one assay cycle). In addition, the electrochemical signals were not significantly affected by possible interferences which could be present in the real samples. Along with the simplicity of automation, this makes the developed method a promising tool for use in water quality assessment. Full article
(This article belongs to the Special Issue Sensors for Toxic and Pathogen Detection)
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Open AccessArticle Light Emitting Marker for Robust Vision-Based On-The-Spot Bacterial Growth Detection
Sensors 2017, 17(6), 1459; doi:10.3390/s17061459
Received: 2 April 2017 / Revised: 6 June 2017 / Accepted: 19 June 2017 / Published: 21 June 2017
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Abstract
Simple methods using the striped pattern paper marker and FFT (fast Fourier transformation) have been proposed as alternatives to measuring the optical density for determining the level of bacterial growth. The marker-based method can be easily automated, but due to image-processing-base of the
[...] Read more.
Simple methods using the striped pattern paper marker and FFT (fast Fourier transformation) have been proposed as alternatives to measuring the optical density for determining the level of bacterial growth. The marker-based method can be easily automated, but due to image-processing-base of the method, the presence of light or the color of the culture broth can disturb the detection process. This paper proposes a modified version of marker-FFT-based growth detection that uses a light emitting diode (LED) array as a marker. Since the marker itself can emit the light, the measurements can be performed even when there is no light source or the bacteria are cultured in a large volume of darkly colored broth. In addition, an LED marker can function as a region of interest (ROI) indicator in the image. We expect that the proposed LED-based marker system will allow more robust growth detection compared to conventional methods. Full article
(This article belongs to the Special Issue Sensors for Toxic and Pathogen Detection)
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Open AccessArticle Identification of Pathogenic Factors in Klebsiella pneumoniae Using Impedimetric Sensor Equipped with Biomimetic Surfaces
Sensors 2017, 17(6), 1406; doi:10.3390/s17061406
Received: 11 April 2017 / Revised: 17 May 2017 / Accepted: 9 June 2017 / Published: 15 June 2017
Cited by 1 | PDF Full-text (2814 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
K. pneumoniae is an opportunistic pathogen that causes nosocomial infections, such as, pneumonia, urinary tract infections, septic shock, and gastro intestinal disease. Lipopolysaccharide (LPS), capsular polysaccharide, and fimbriae are recognized major virulence factors of K. pneumoniae and play key roles during early stages
[...] Read more.
K. pneumoniae is an opportunistic pathogen that causes nosocomial infections, such as, pneumonia, urinary tract infections, septic shock, and gastro intestinal disease. Lipopolysaccharide (LPS), capsular polysaccharide, and fimbriae are recognized major virulence factors of K. pneumoniae and play key roles during early stages of infections. In this study, we functionalized the surface of gold electrode with mannose and mucin to monitor the adhesion-associated virulence factors of K. pneumoniae. The binding characteristics of K. pneumoniae 2242 wild type and of its isogenic mutants lacking outer-core LPS (∆wabG) or fimbriae (∆fimA) were investigated using Faradaic impedance spectra. The results obtained showed fimbriae are responsible for K. pneumoniae adhesion to the mannose of glycoprotein on the surfaces of epithelial cells, whereas outer-core LPS and capsular polysaccharide are associated with specific binding to mucous. These results concurred with those of a conventional in vitro assay using human ileocecal epithelial cell (HCT-8 cells) and a human bladder epithelial cell (T-24), indicating that the devised method could be useful for investigating virulence-associated interactions of pathogenic bacteria with specific host cells and organs. Full article
(This article belongs to the Special Issue Sensors for Toxic and Pathogen Detection)
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Open AccessArticle Rapid Waterborne Pathogen Detection with Mobile Electronics
Sensors 2017, 17(6), 1348; doi:10.3390/s17061348
Received: 16 April 2017 / Revised: 28 May 2017 / Accepted: 7 June 2017 / Published: 9 June 2017
PDF Full-text (2019 KB) | HTML Full-text | XML Full-text
Abstract
Pathogen detection in water samples, without complex and time consuming procedures such as fluorescent-labeling or culture-based incubation, is essential to public safety. We propose an immunoagglutination-based protocol together with the microfluidic device to quantify pathogen levels directly from water samples. Utilizing ubiquitous complementary
[...] Read more.
Pathogen detection in water samples, without complex and time consuming procedures such as fluorescent-labeling or culture-based incubation, is essential to public safety. We propose an immunoagglutination-based protocol together with the microfluidic device to quantify pathogen levels directly from water samples. Utilizing ubiquitous complementary metal–oxide–semiconductor (CMOS) imagers from mobile electronics, a low-cost and one-step reaction detection protocol is developed to enable field detection for waterborne pathogens. 10 mL of pathogen-containing water samples was processed using the developed protocol including filtration enrichment, immune-reaction detection and imaging processing. The limit of detection of 10 E. coli O157:H7 cells/10 mL has been demonstrated within 10 min of turnaround time. The protocol can readily be integrated into a mobile electronics such as smartphones for rapid and reproducible field detection of waterborne pathogens. Full article
(This article belongs to the Special Issue Sensors for Toxic and Pathogen Detection)
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Open AccessArticle Magnetic Lateral Flow Strip for the Detection of Cocaine in Urine by Naked Eyes and Smart Phone Camera
Sensors 2017, 17(6), 1286; doi:10.3390/s17061286
Received: 1 April 2017 / Revised: 13 May 2017 / Accepted: 22 May 2017 / Published: 5 June 2017
PDF Full-text (2047 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Magnetic lateral flow strip (MLFS) based on magnetic bead (MB) and smart phone camera has been developed for quantitative detection of cocaine (CC) in urine samples. CC and CC-bovine serum albumin (CC-BSA) could competitively react with MB-antibody (MB-Ab) of CC on the surface
[...] Read more.
Magnetic lateral flow strip (MLFS) based on magnetic bead (MB) and smart phone camera has been developed for quantitative detection of cocaine (CC) in urine samples. CC and CC-bovine serum albumin (CC-BSA) could competitively react with MB-antibody (MB-Ab) of CC on the surface of test line of MLFS. The color of MB-Ab conjugate on the test line relates to the concentration of target in the competition immunoassay format, which can be used as a visual signal. Furthermore, the color density of the MB-Ab conjugate can be transferred into digital signal (gray value) by a smart phone, which can be used as a quantitative signal. The linear detection range for CC is 5–500 ng/mL and the relative standard deviations are under 10%. The visual limit of detection was 5 ng/mL and the whole analysis time was within 10 min. The MLFS has been successfully employed for the detection of CC in urine samples without sample pre-treatment and the result is also agreed to that of enzyme-linked immunosorbent assay (ELISA). With the popularization of smart phone cameras, the MLFS has large potential in the detection of drug residues in virtue of its stability, speediness, and low-cost. Full article
(This article belongs to the Special Issue Sensors for Toxic and Pathogen Detection)
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Open AccessArticle Supramolecular Recognition of Escherichia coli Bacteria by Fluorescent Oligo(Phenyleneethynylene)s with Mannopyranoside Termini Groups
Sensors 2017, 17(5), 1025; doi:10.3390/s17051025
Received: 24 January 2017 / Revised: 15 March 2017 / Accepted: 11 April 2017 / Published: 4 May 2017
Cited by 1 | PDF Full-text (4231 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Escherichia coli is one the most common bacteria responsible of uropathogenic diseases, which motives the search for rapid and easy methods of detection. By taking advantage of the specific interactions between mannose and type 1 fimbriae, in this work two fluorescent phenyleneethynylene (PE)
[...] Read more.
Escherichia coli is one the most common bacteria responsible of uropathogenic diseases, which motives the search for rapid and easy methods of detection. By taking advantage of the specific interactions between mannose and type 1 fimbriae, in this work two fluorescent phenyleneethynylene (PE) trimers bearing one or two 4-aminophenyl-α-D-mannopyranoside termini groups were synthesized for the detection of E. coli. Three bacterial strains: ORN 178 (fimbriae I expression), ORN 208 (mutant serotype with no fimbriae expression) and one obtained from a local hospital (SS3) were used. Laser Scanning Confocal Microscopy (LSCM) and Surface Plasmon Resonance (SPR) were applied for the interaction studies following two different approaches: (1) mixing the oligomer solutions with the bacterial suspension, which permitted the observation of stained bacteria and by (2) biosensing as thin films, where bacteria adhered on the surface-functionalized substrate. LSCM allows one to easily visualize that two mannose groups are necessary to have a specific interaction with the fimbriae 1. The sensitivity of SPR assays to E. coli was 104 colony forming unit (CFU)/mL at 50 µL/min flow rate. The combination of PE units with two mannose groups results in a novel molecule that can be used as a specific fluorescent marker as well as a transducer for the detection of E. coli. Full article
(This article belongs to the Special Issue Sensors for Toxic and Pathogen Detection)
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Open AccessArticle Characterization of N-Acyl Homoserine Lactones in Vibrio tasmaniensis LGP32 by a Biosensor-Based UHPLC-HRMS/MS Method
Sensors 2017, 17(4), 906; doi:10.3390/s17040906
Received: 4 April 2017 / Revised: 14 April 2017 / Accepted: 17 April 2017 / Published: 20 April 2017
Cited by 1 | PDF Full-text (282 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Since the discovery of quorum sensing (QS) in the 1970s, many studies have demonstrated that Vibrio species coordinate activities such as biofilm formation, virulence, pathogenesis, and bioluminescence, through a large group of molecules called N-acyl homoserine lactones (AHLs). However, despite the extensive
[...] Read more.
Since the discovery of quorum sensing (QS) in the 1970s, many studies have demonstrated that Vibrio species coordinate activities such as biofilm formation, virulence, pathogenesis, and bioluminescence, through a large group of molecules called N-acyl homoserine lactones (AHLs). However, despite the extensive knowledge on the involved molecules and the biological processes controlled by QS in a few selected Vibrio strains, less is known about the overall diversity of AHLs produced by a broader range of environmental strains. To investigate the prevalence of QS capability of Vibrio environmental strains we analyzed 87 Vibrio spp. strains from the Banyuls Bacterial Culture Collection (WDCM911) for their ability to produce AHLs. This screening was based on three biosensors, which cover a large spectrum of AHLs, and revealed that only 9% of the screened isolates produced AHLs in the defined experimental conditions. Among these AHL-producing strains, Vibrio tasmaniensis LGP32 is a well-known pathogen of bivalves. We further analyzed the diversity of AHLs produced by this strain using a sensitive bioguided UHPLC-HRMS/MS approach (Ultra-High-Performance Liquid Chromatography followed by High-Resolution tandem Mass Spectrometry) and we identified C10-HSL, OH-C12-HSL, oxo-C12-HSL and C14:1-HSL as QS molecules. This is the first report that documents the production of AHL by Vibrio tasmaniensis LGP32. Full article
(This article belongs to the Special Issue Sensors for Toxic and Pathogen Detection)
Open AccessArticle Strategy for Accurate Detection of Escherichia coli O157:H7 in Ground Pork Using a Lateral Flow Immunoassay
Sensors 2017, 17(4), 753; doi:10.3390/s17040753
Received: 9 February 2017 / Revised: 21 March 2017 / Accepted: 28 March 2017 / Published: 2 April 2017
PDF Full-text (898 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Escherichia coli O157:H7 is known to cause serious diseases including hemorrhagic colitis and hemolytic uremic syndrome. A gold nanoparticle lateral flow immunoassay (Au-LFIA) was used to detect Escherichia coli O157:H7 in ground pork samples. False-positive results were detected using Au-LFIA; a Citrobacter freundii
[...] Read more.
Escherichia coli O157:H7 is known to cause serious diseases including hemorrhagic colitis and hemolytic uremic syndrome. A gold nanoparticle lateral flow immunoassay (Au-LFIA) was used to detect Escherichia coli O157:H7 in ground pork samples. False-positive results were detected using Au-LFIA; a Citrobacter freundii strain was isolated from the ground pork samples and identified by using CHROmagarTM plates, API 20E, and 16S RNA sequencing. Since C. freundii showed cross-reactivity with E. coli O157:H7 when Au-LFIA test strips were used, a novel method combining modified enrichment with a lateral flow immunoassay for accurate and convenient detection of E. coli O157:H7 in ground pork was developed in this study to minimize these false positives. MacConkey broth was optimized for E. coli O157:H7 enrichment and C. freundii inhibition by the addition of 5 mg/L potassium tellurite and 0.10 mg/L cefixime. Using the proposed modified enrichment procedure, the false-positive rate of ground pork samples spiked with 100 CFU/g C. freundii decreased to 5%. Full article
(This article belongs to the Special Issue Sensors for Toxic and Pathogen Detection)
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Open AccessArticle Design and Elementary Evaluation of a Highly-Automated Fluorescence-Based Instrument System for On-Site Detection of Food-Borne Pathogens
Sensors 2017, 17(3), 442; doi:10.3390/s17030442
Received: 27 December 2016 / Revised: 15 February 2017 / Accepted: 21 February 2017 / Published: 23 February 2017
PDF Full-text (5992 KB) | HTML Full-text | XML Full-text
Abstract
A simple, highly-automated instrument system used for on-site detection of foodborne pathogens based on fluorescence was designed, fabricated, and preliminarily tested in this paper. A corresponding method has been proved effective in our previous studies. This system utilizes a light-emitting diode (LED) to
[...] Read more.
A simple, highly-automated instrument system used for on-site detection of foodborne pathogens based on fluorescence was designed, fabricated, and preliminarily tested in this paper. A corresponding method has been proved effective in our previous studies. This system utilizes a light-emitting diode (LED) to excite fluorescent labels and a spectrometer to record the fluorescence signal from samples. A rotation stage for positioning and switching samples was innovatively designed for high-throughput detection, ten at most in one single run. We also developed software based on LabVIEW for data receiving, processing, and the control of the whole system. In the test of using a pure quantum dot (QD) solution as a standard sample, detection results from this home-made system were highly-relevant with that from a well-commercialized product and even slightly better reproducibility was found. And in the test of three typical kinds of food-borne pathogens, fluorescence signals recorded by this system are highly proportional to the variation of the sample concentration, with a satisfied limit of detection (LOD) (nearly 102–103 CFU·mL−1 in food samples). Additionally, this instrument system is low-cost and easy-to-use, showing a promising potential for on-site rapid detection of food-borne pathogens. Full article
(This article belongs to the Special Issue Sensors for Toxic and Pathogen Detection)
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Review

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Open AccessReview Microbial Fuels Cell-Based Biosensor for Toxicity Detection: A Review
Sensors 2017, 17(10), 2230; doi:10.3390/s17102230
Received: 29 July 2017 / Revised: 19 September 2017 / Accepted: 21 September 2017 / Published: 28 September 2017
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Abstract
With the unprecedented deterioration of environmental quality, rapid recognition of toxic compounds is paramount for performing in situ real-time monitoring. Although several analytical techniques based on electrochemistry or biosensors have been developed for the detection of toxic compounds, most of them are time-consuming,
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With the unprecedented deterioration of environmental quality, rapid recognition of toxic compounds is paramount for performing in situ real-time monitoring. Although several analytical techniques based on electrochemistry or biosensors have been developed for the detection of toxic compounds, most of them are time-consuming, inaccurate, or cumbersome for practical applications. More recently, microbial fuel cell (MFC)-based biosensors have drawn increasing interest due to their sustainability and cost-effectiveness, with applications ranging from the monitoring of anaerobic digestion process parameters (VFA) to water quality detection (e.g., COD, BOD). When a MFC runs under correct conditions, the voltage generated is correlated with the amount of a given substrate. Based on this linear relationship, several studies have demonstrated that MFC-based biosensors could detect heavy metals such as copper, chromium, or zinc, as well as organic compounds, including p-nitrophenol (PNP), formaldehyde and levofloxacin. Both bacterial consortia and single strains can be used to develop MFC-based biosensors. Biosensors with single strains show several advantages over systems integrating bacterial consortia, such as selectivity and stability. One of the limitations of such sensors is that the detection range usually exceeds the actual pollution level. Therefore, improving their sensitivity is the most important for widespread application. Nonetheless, MFC-based biosensors represent a promising approach towards single pollutant detection. Full article
(This article belongs to the Special Issue Sensors for Toxic and Pathogen Detection)
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Open AccessReview Multifunctional Nanotechnology-Enabled Sensors for Rapid Capture and Detection of Pathogens
Sensors 2017, 17(9), 2121; doi:10.3390/s17092121
Received: 12 August 2017 / Revised: 4 September 2017 / Accepted: 7 September 2017 / Published: 15 September 2017
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Abstract
Nanomaterial-based sensing approaches that incorporate different types of nanoparticles (NPs) and nanostructures in conjunction with natural or synthetic receptors as molecular recognition elements provide opportunities for the design of sensitive and selective assays for rapid detection of contaminants. This review summarizes recent advancements
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Nanomaterial-based sensing approaches that incorporate different types of nanoparticles (NPs) and nanostructures in conjunction with natural or synthetic receptors as molecular recognition elements provide opportunities for the design of sensitive and selective assays for rapid detection of contaminants. This review summarizes recent advancements over the past ten years in the development of nanotechnology-enabled sensors and systems for capture and detection of pathogens. The most common types of nanostructures and NPs, their modification with receptor molecules and integration to produce viable sensing systems with biorecognition, amplification and signal readout are discussed. Examples of all-in-one systems that combine multifunctional properties for capture, separation, inactivation and detection are also provided. Current trends in the development of low-cost instrumentation for rapid assessment of food contamination are discussed as well as challenges for practical implementation and directions for future research. Full article
(This article belongs to the Special Issue Sensors for Toxic and Pathogen Detection)
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Open AccessReview An Overview on Recent Progress in Electrochemical Biosensors for Antimicrobial Drug Residues in Animal-Derived Food
Sensors 2017, 17(9), 1947; doi:10.3390/s17091947
Received: 18 July 2017 / Revised: 9 August 2017 / Accepted: 22 August 2017 / Published: 24 August 2017
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Abstract
Anti-microbial drugs are widely employed for the treatment and cure of diseases in animals, promotion of animal growth, and feed efficiency. However, the scientific literature has indicated the possible presence of antimicrobial drug residues in animal-derived food, making it one of the key
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Anti-microbial drugs are widely employed for the treatment and cure of diseases in animals, promotion of animal growth, and feed efficiency. However, the scientific literature has indicated the possible presence of antimicrobial drug residues in animal-derived food, making it one of the key public concerns for food safety. Therefore, it is highly desirable to design fast and accurate methodologies to monitor antimicrobial drug residues in animal-derived food. Legislation is in place in many countries to ensure antimicrobial drug residue quantities are less than the maximum residue limits (MRL) defined on the basis of food safety. In this context, the recent years have witnessed a special interest in the field of electrochemical biosensors for food safety, based on their unique analytical features. This review article is focused on the recent progress in the domain of electrochemical biosensors to monitor antimicrobial drug residues in animal-derived food. Full article
(This article belongs to the Special Issue Sensors for Toxic and Pathogen Detection)
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Open AccessReview Electrochemical Biosensors for Rapid Detection of Foodborne Salmonella: A Critical Overview
Sensors 2017, 17(8), 1910; doi:10.3390/s17081910
Received: 5 July 2017 / Revised: 13 August 2017 / Accepted: 13 August 2017 / Published: 18 August 2017
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Abstract
Abstract: Salmonella has represented the most common and primary cause of food poisoning in many countries for at least over 100 years. Its detection is still primarily based on traditional microbiological culture methods which are labor-intensive, extremely time consuming, and not suitable
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Abstract: Salmonella has represented the most common and primary cause of food poisoning in many countries for at least over 100 years. Its detection is still primarily based on traditional microbiological culture methods which are labor-intensive, extremely time consuming, and not suitable for testing a large number of samples. Accordingly, great efforts to develop rapid, sensitive and specific methods, easy to use, and suitable for multi-sample analysis, have been made and continue. Biosensor-based technology has all the potentialities to meet these requirements. In this paper, we review the features of the electrochemical immunosensors, genosensors, aptasensors and phagosensors developed in the last five years for Salmonella detection, focusing on the critical aspects of their application in food analysis. Full article
(This article belongs to the Special Issue Sensors for Toxic and Pathogen Detection)
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Open AccessFeature PaperReview Detection Methodologies for Pathogen and Toxins: A Review
Sensors 2017, 17(8), 1885; doi:10.3390/s17081885
Received: 21 June 2017 / Revised: 2 August 2017 / Accepted: 14 August 2017 / Published: 16 August 2017
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Abstract
Pathogen and toxin-contaminated foods and beverages are a major source of illnesses, even death, and have a significant economic impact worldwide. Human health is always under a potential threat, including from biological warfare, due to these dangerous pathogens. The agricultural and food production
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Pathogen and toxin-contaminated foods and beverages are a major source of illnesses, even death, and have a significant economic impact worldwide. Human health is always under a potential threat, including from biological warfare, due to these dangerous pathogens. The agricultural and food production chain consists of many steps such as harvesting, handling, processing, packaging, storage, distribution, preparation, and consumption. Each step is susceptible to threats of environmental contamination or failure to safeguard the processes. The production process can be controlled in the food and agricultural sector, where smart sensors can play a major role, ensuring greater food quality and safety by low cost, fast, reliable, and profitable methods of detection. Techniques for the detection of pathogens and toxins may vary in cost, size, and specificity, speed of response, sensitivity, and precision. Smart sensors can detect, analyse and quantify at molecular levels contents of different biological origin and ensure quality of foods against spiking with pesticides, fertilizers, dioxin, modified organisms, anti-nutrients, allergens, drugs and so on. This paper reviews different methodologies to detect pathogens and toxins in foods and beverages. Full article
(This article belongs to the Special Issue Sensors for Toxic and Pathogen Detection)
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