Immobilized optical fiber microprobe for selective and sensitive Escherichia coli detection

2018 ◽  
pp. e201700162
Author(s):  
Yanpeng Li ◽  
Hui Ma ◽  
Lin Gan ◽  
Andong Gong ◽  
Haibin Zhang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Optical Fiber

Optofluidic manipulation of Escherichia coli in a microfluidic channel using an abruptly tapered optical fiber

2013 ◽  
Vol 103 (3) ◽  
pp. 033703 ◽  
Author(s):  
Hongbao Xin ◽  
Yayi Li ◽  
Lingshan Li ◽  
Rui Xu ◽  
Baojun Li
Keyword(s):  
Escherichia Coli ◽  
Optical Fiber ◽  
Microfluidic Channel ◽  
Tapered Optical Fiber

High sensitive and selective Escherichia coli detection using immobilized optical fiber microprobe

2017 ◽  
Author(s):  
Yanpeng Li ◽  
Qizhen Sun ◽  
Yiyang Luo ◽  
Yue Li ◽  
Andong Gong ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Optical Fiber

Detection of Escherichia coli O157:H7 in 10- and 25-Gram Ground Beef Samples with an Evanescent-Wave Biosensor with Silica and Polystyrene Waveguides

2002 ◽  
Vol 65 (4) ◽  
pp. 596-602 ◽  
Author(s):  
DANIEL R. DeMARCO ◽  
DANIEL V. LIM
Keyword(s):  
Escherichia Coli ◽  
Optical Fiber ◽  
Evanescent Wave ◽  
Ground Beef ◽  
False Positives ◽  
Evanescent Field ◽  
Escherichia Coli O157 ◽  
Fiber Probe ◽  
Fluorescent Signal ◽  
E Coli

A portable evanescent-wave fiber-optic biosensor was used to detect Escherichia coli O157:H7 in seeded 10- and 25-g ground beef samples. The biosensor works by launching light from a 635-nm laser diode into specially designed optical fiber probes, generating an evanescent field that extends approximately 1,000 nm from the fiber surface. Fluorescent molecules within the evanescent field are excited, and a portion of their emission recouples into the fiber probe. The return path emission is transported by an optical fiber to a photodiode within the biosensor that detects and quantifies the fluorescent signal. A sandwich immunoassay was performed on the fiber probes with cyanine 5 dye–labeled polyclonal anti–E. coli O157:H7 antibodies for generation of the specific fluorescent signal. Biotin-streptavidin interactions were used to attach polyclonal antiE. coli O157:H7 antibodies to the surface of the fiber probe. A centrifugation method was developed to obtain samples suitable for biosensor analysis from 10- and 25-g ground beef samples. The assay was shown to be sensitive and repeatable. One hundred percent correct identification of positive samples was demonstrated at 9.0 × 103 CFU/g for 25-g ground beef samples with silica waveguides and at 5.2 × 102 CFU/g for 10-g ground beef samples with polystyrene waveguides. The reaction was highly specific. No false positives were observed for 10-g ground beef samples not spiked with the pathogen. In addition, when samples were spiked with high concentrations of a variety of non–E. coli O157:H7 organisms, no false positives were observed. The method was rapid, with results being obtained within 25 min of sample processing.

scholarly journals A novel plus shaped cavity based optical fiber sensor for the detection of Escherichia-Coli

2021 ◽  
Vol 5 ◽  
pp. 100156
Author(s):  
Lokendra Singh ◽  
Gaurav Kumar ◽  
Siddharth Jain ◽  
Brajesh Kumar Kaushik
Keyword(s):  
Escherichia Coli ◽  
Optical Fiber ◽  
Optical Fiber Sensor ◽  
Fiber Sensor

scholarly journals Sensitivity Analysis of Different Shapes of a Plastic Optical Fiber-Based Immunosensor for Escherichia coli: Simulation and Experimental Results

Sensors ◽  
2017 ◽  
Vol 17 (12) ◽  
pp. 2944 ◽  
Author(s):  
Domingos Rodrigues ◽  
Rafaela Lopes ◽  
Marcos Franco ◽  
Marcelo Werneck ◽  
Regina Allil
Keyword(s):  
Escherichia Coli ◽  
Sensitivity Analysis ◽  
Optical Fiber ◽  
Experimental Results ◽  
Plastic Optical Fiber ◽  
Different Shapes

Structural organization of escherichia coli ribosomes as determined by immuno electron microscopy

1978 ◽  
Vol 36 (2) ◽  
pp. 166-167 ◽  
Author(s):  
G. Stöffler ◽  
R.W. Bald ◽  
J. Dieckhoff ◽  
H. Eckhard ◽  
R. Lührmann ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Escherichia Coli ◽  
Ribosomal Proteins ◽  
Structural Organization ◽  
Three Dimensional ◽  
Ribosomal Subunit ◽  
Spatial Arrangement ◽  
Small Subunit ◽  
Antibody Binding ◽  
Immuno Electron Microscopy

A central step towards an understanding of the structure and function of the Escherichia coli ribosome, a large multicomponent assembly, is the elucidation of the spatial arrangement of its 54 proteins and its three rRNA molecules. The structural organization of ribosomal components has been investigated by a number of experimental approaches. Specific antibodies directed against each of the 54 ribosomal proteins of Escherichia coli have been performed to examine antibody-subunit complexes by electron microscopy. The position of the bound antibody, specific for a particular protein, can be determined; it indicates the location of the corresponding protein on the ribosomal surface.The three-dimensional distribution of each of the 21 small subunit proteins on the ribosomal surface has been determined by immuno electron microscopy: the 21 proteins have been found exposed with altogether 43 antibody binding sites. Each one of 12 proteins showed antibody binding at remote positions on the subunit surface, indicating highly extended conformations of the proteins concerned within the 30S ribosomal subunit; the remaining proteins are, however, not necessarily globular in shape (Fig. 1).

Sites of Adsorption of the Bacteriophages T3 and T5 on the Wall of Escherichia Coli B.

1967 ◽  
Vol 25 ◽  
pp. 96-97
Author(s):  
Manfred E. Bayer
Keyword(s):  
Escherichia Coli ◽  
Cell Wall ◽  
Electron Microscope ◽  
Uranyl Acetate ◽  
E Coli ◽  
Receptor Sites ◽  
Rigid Cell Wall ◽  
Host Cell Surface ◽  
Bacterial Viruses ◽  
Escherichia Coli B

Bacterial viruses adsorb specifically to receptors on the host cell surface. Although the chemical composition of some of the cell wall receptors for bacteriophages of the T-series has been described and the number of receptor sites has been estimated to be 150 to 300 per E. coli cell, the localization of the sites on the bacterial wall has been unknown.When logarithmically growing cells of E. coli are transferred into a medium containing 20% sucrose, the cells plasmolize: the protoplast shrinks and becomes separated from the somewhat rigid cell wall. When these cells are fixed in 8% Formaldehyde, post-fixed in OsO4/uranyl acetate, embedded in Vestopal W, then cut in an ultramicrotome and observed with the electron microscope, the separation of protoplast and wall becomes clearly visible, (Fig. 1, 2). At a number of locations however, the protoplasmic membrane adheres to the wall even under the considerable pull of the shrinking protoplast. Thus numerous connecting bridges are maintained between protoplast and cell wall. Estimations of the total number of such wall/membrane associations yield a number of about 300 per cell.

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