DNA aptamer-based non-faradaic impedance biosensor for detecting E. coli

Abstract This work presents the surface modification of silicon chips as a platform for silicon-based biosensors with applications aiming for the detection of foodborne bacteria in aqueous solution. The detection requires high selectivity as the solution may contain a variety of biological species, which affect the outcome of the sensing process. The silicon surface is functionalized by a self-assembled monolayer (SAM) with thiol groups followed by immobilizing a thiol-linked DNA aptamer. The DNA aptamer used in this work has reported to recognize a biological species, E. coli ATCC 25922. The presence of DNA aptamer on the sensor surface allows the capture of the specific E. coli cells on the surface, while other potential biological (and chemical) species would not attach to the sensor surface, thus improving the selectivity of the sensor. The uniform formation of the SAM on the surface is an important step toward uniformly coating the sensor surface with the desired DNA aptamer. The SAM is created on the silicon surface by surface modification with the MPTS (3-mercaptopropyl trimethoxy silane) solution. Then the aptamer DNA solution is applied as droplets on the chip followed by a cure process. The attachment of the SAM and DNA aptamers are verified by atomic force microscopy (AFM). The surface functionalization presented in this work can be used for sensors made of silicon coated with a thin layer of native oxide, and can be adopted for detection of other cells and biological agents using the proper SAM and DNA aptamer.

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A label-free DNA aptamer-based impedance biosensor for the detection of E. coli outer membrane proteins

Sensors and Actuators B Chemical ◽

10.1016/j.snb.2013.01.062 ◽

2013 ◽

Vol 181 ◽

pp. 766-772 ◽

Cited By ~ 45

Author(s):

Raquel B. Queirós ◽

N. de-los-Santos-Álvarez ◽

J.P. Noronha ◽

M.G.F. Sales

Keyword(s):

Membrane Proteins ◽

Outer Membrane ◽

Outer Membrane Proteins ◽

Dna Aptamer ◽

Label Free ◽

E Coli ◽

Free Dna

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Highly Portable and Sensitive Filter-Based Antibody-or DNA Aptamer-Enzyme-Linked Fluorescence Detection of Potential Bacterial Pathogens Proximal to Agricultural Fields

Advanced Science Engineering and Medicine ◽

10.1166/asem.2020.2627 ◽

2020 ◽

Vol 12 (7) ◽

pp. 909-913

Author(s):

John G. Bruno

Keyword(s):

Membrane Filtration ◽

Dna Aptamer ◽

Bacterial Cells ◽

E Coli ◽

Filter Surface ◽

Processing Times ◽

Escherchia Coli ◽

Portable System ◽

Filtration Unit ◽

Streptavidin Peroxidase

A novel, sensitive, rapid and highly portable system consisting of a membrane filtration unit connected to a large syringe with tubing was used to detect Escherchia coli and Salmonella enterica bacteria in a mobile laboratory setting. These simple fluorescent enzyme-linked molecular assays consisted of biotinylated DNA aptamers or antibodies which were allowed to bind the target bacteria and be deposited on 0.45 μm pore size membrane filters by suction, followed by binding of streptavidin-peroxidase conjugate, wash steps and development in Amplex® UltraRed (AUR; resazurin derivative) with hydrogen peroxide activation. Fluorescence values of developed AUR from the filter surface were assessed with a commercially-available handheld fluorometer. Preliminary data indicate detection limits in the range of 50–110 E. coli and Salmonella bacterial cells per sample with good specificity and total processing times under one hour.

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DNA aptamer identification and characterization for E. coli O157 detection using cell based SELEX method

Analytical Biochemistry ◽

10.1016/j.ab.2017.08.005 ◽

2017 ◽

Vol 536 ◽

pp. 36-44 ◽

Cited By ~ 24

Author(s):

Masoum Amraee ◽

Mana Oloomi ◽

Afsaneh Yavari ◽

Saeid Bouzari

Keyword(s):

Dna Aptamer ◽

E Coli ◽

Identification And Characterization

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Evanescent wave DNA-aptamer biosensor based on long period gratings for the specific recognition of E. coli outer membrane proteins

Biosensors and Bioelectronics ◽

10.1016/j.bios.2014.06.062 ◽

2014 ◽

Vol 62 ◽

pp. 227-233 ◽

Cited By ~ 34

Author(s):

R.B. Queirós ◽

C. Gouveia ◽

J.R.A. Fernandes ◽

P.A.S. Jorge

Keyword(s):

Membrane Proteins ◽

Outer Membrane ◽

Evanescent Wave ◽

Outer Membrane Proteins ◽

Dna Aptamer ◽

E Coli ◽

Long Period ◽

Specific Recognition ◽

Long Period Gratings

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Endotoxin Alteration of the Mucopolysaccharide Blood Vessel Coating in Rats

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100050755 ◽

1974 ◽

Vol 32 ◽

pp. 148-149

Author(s):

D. E. Philpott ◽

A. Takahashi

Keyword(s):

Skeletal Muscle ◽

Endothelial Cells ◽

Salivary Gland ◽

Carotid Artery ◽

Basement Membrane ◽

Coronary Vessels ◽

Ruthenium Red ◽

E Coli ◽

Old Rats ◽

The Brain

Two month, eight month and two year old rats were treated with 10 or 20 mg/kg of E. Coli endotoxin I. P. The eight month old rats proved most resistant to the endotoxin. During fixation the aorta, carotid artery, basil arartery of the brain, coronary vessels of the heart, inner surfaces of the heart chambers, heart and skeletal muscle, lung, liver, kidney, spleen, brain, retina, trachae, intestine, salivary gland, adrenal gland and gingiva were treated with ruthenium red or alcian blue to preserve the mucopolysaccharide (MPS) coating. Five, 8 and 24 hrs of endotoxin treatment produced increasingly marked capillary damage, disappearance of the MPS coating, edema, destruction of endothelial cells and damage to the basement membrane in the liver, kidney and lung.

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Ribosome Structural Organization

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100051670 ◽

1974 ◽

Vol 32 ◽

pp. 332-333

Author(s):

James A. Lake

Keyword(s):

Ribosomal Proteins ◽

Structural Organization ◽

Three Dimensional ◽

Small Subunit ◽

Structural Studies ◽

X Ray Diffraction ◽

Specific Antibodies ◽

X Ray ◽

E Coli ◽

Complete Sequences

The understanding of ribosome structure has advanced considerably in the last several years. Biochemists have characterized the constituent proteins and rRNA's of ribosomes. Complete sequences have been determined for some ribosomal proteins and specific antibodies have been prepared against all E. coli small subunit proteins. In addition, a number of naturally occuring systems of three dimensional ribosome crystals which are suitable for structural studies have been observed in eukaryotes. Although the crystals are, in general, too small for X-ray diffraction, their size is ideal for electron microscopy.

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

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100060490 ◽

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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Emigration of neutrophils in the central nervous system

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100077517 ◽

1983 ◽

Vol 41 ◽

pp. 788-789

Author(s):

John L.Beggs ◽

John D. Waggener ◽

Wanda Miller ◽

Jane Watkins

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Osmium Tetroxide ◽

White Blood Cells ◽

Arterial Perfusion ◽

E Coli ◽

Intracisternal Injection ◽

The Central Nervous System ◽

Brain And Spinal Cord ◽

Interendothelial Junctions

Studies using mesenteric and ear chamber preparations have shown that interendothelial junctions provide the route for neutrophil emigration during inflammation. The term emigration refers to the passage of white blood cells across the endothelium from the vascular lumen. Although the precise pathway of transendo- thelial emigration in the central nervous system (CNS) has not been resolved, the presence of different physiological and morphological (tight junctions) properties of CNS endothelium may dictate alternate emigration pathways.To study neutrophil emigration in the CNS, we induced meningitis in guinea pigs by intracisternal injection of E. coli bacteria.In this model, leptomeningeal inflammation is well developed by 3 hr. After 3 1/2 hr, animals were sacrificed by arterial perfusion with 3% phosphate buffered glutaraldehyde. Tissues from brain and spinal cord were post-fixed in 1% osmium tetroxide, dehydrated in alcohols and propylene oxide, and embedded in Epon. Thin serial sections were cut with diamond knives and examined in a Philips 300 electron microscope.

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Use of Uranium-Labeled Antibodies for Electron Microscopic Localization of Various Antigens in Mammalian Cells

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100060696 ◽

1967 ◽

Vol 25 ◽

pp. 136-137

Author(s):

J. P. Petrali ◽

E. J. Donati ◽

L. A. Sternberger

Keyword(s):

Endoplasmic Reticulum ◽

Hela Cells ◽

Mammalian Cells ◽

Specific Antiserum ◽

Electron Microscopic ◽

E Coli ◽

Cytoplasmic Membranes ◽

Viral Progeny ◽

Ultrathin Sections ◽

Electron Microscopic Localization

Specific contrast is conferred to subcellular antigen by applying purified antibodies, exhaustively labeled with uranium under immunospecific protection, to ultrathin sections. Use of Seligman’s principle of bridging osmium to metal via thiocarbohydrazide (TCH) intensifies specific contrast. Ultrathin sections of osmium-fixed materials were stained on the grid by application of 1) thiosemicarbazide (TSC), 2) unlabeled specific antiserum, 3) uranium-labeled anti-antibody and 4) TCH followed by reosmication. Antigens to be localized consisted of vaccinia antigen in infected HeLa cells, lysozyme in monocytes of patients with monocytic or monomyelocytic leukemia, and fibrinogen in the platelets of these leukemic patients. Control sections were stained with non-specific antiserum (E. coli).In the vaccinia-HeLa system, antigen was localized from 1 to 3 hours following infection, and was confined to degrading virus, the inner walls of numerous organelles, and other structures in cytoplasmic foci. Surrounding architecture and cellular mitochondria were unstained. 8 to 14 hours after infection, antigen was localized on the outer walls of the viral progeny, on cytoplasmic membranes, and free in the cytoplasm. Staining of endoplasmic reticulum was intense and focal early, and weak and diffuse late in infection.

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