Reagentless optical biosensor

Grace, Karen M.; Goeller, Roy M.; Grace, W. Kevin; Kolar, J. D.; Morrison, Leeland J; Sweet, M.R.; Wiig, L Gary; Reed, Scott M.; Lauer, Sabine A.; Little, Kristin M.; Bustos, Gerrie L.; Anderson, Aaron S.; Swanson, Basil I.

doi:10.1117/12.516372

Cited by 4 publications

(10 citation statements)

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“…The resulting surface-bound bilayers can be used in sensing by attaching a capture element (such as biotin) or adding in a small amount of a functionalized lipid; the functional moiety is usually kept to a small percentage to minimize non-specific binding [ 22 ]. Several antigens have been detected using these surfaces, including Bacillus anthracis protective antigen (PA) [ 22 , 23 ], carcinoembryonic antigen (CEA) [ 21 , 24 ], Mycobacterium tuberculosis lipoarabinomannan (LAM) [ 25 ], and Vibrio cholerae toxin [ 14 , 15 , 26 ]. Despite the advantages of fluidity, rapid preparation and superb resistance to non-specific binding, as well as low auto-fluorescence at most useful wavelengths, phospholipid bilayers have notable disadvantages with respect to sandwich immunoassays.…”

Section: Functionalization Of Waveguides For Bioassaysmentioning

confidence: 99%

“…First, phospholipids only occur with limited functionality, the most useful being biotin. Assays that use phospholipids often rely on mobile ligands such as GM1 [ 26 ], and must be chosen carefully to select capture agents that insert into lipid bilayers. The second major disadvantage of phospholipid bilayers is instability to some complex fluids (e.g., urine) [ 27 ], detergent rinse, exposure to air, and extended periods of time in storage [ 27 – 29 ].…”

Section: Functionalization Of Waveguides For Bioassaysmentioning

confidence: 99%

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Waveguide-Based Biosensors for Pathogen Detection

Mukundan

Anderson

Grace

et al. 2009

Sensors

169

128

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Optical phenomena such as fluorescence, phosphorescence, polarization, interference and non-linearity have been extensively used for biosensing applications. Optical waveguides (both planar and fiber-optic) are comprised of a material with high permittivity/high refractive index surrounded on all sides by materials with lower refractive indices, such as a substrate and the media to be sensed. This arrangement allows coupled light to propagate through the high refractive index waveguide by total internal reflection and generates an electromagnetic wave—the evanescent field—whose amplitude decreases exponentially as the distance from the surface increases. Excitation of fluorophores within the evanescent wave allows for sensitive detection while minimizing background fluorescence from complex, “dirty” biological samples. In this review, we will describe the basic principles, advantages and disadvantages of planar optical waveguide-based biodetection technologies. This discussion will include already commercialized technologies (e.g., Corning’s EPIC® Ô, SRU Biosystems’ BIND™, Zeptosense®, etc.) and new technologies that are under research and development. We will also review differing assay approaches for the detection of various biomolecules, as well as the thin-film coatings that are often required for waveguide functionalization and effective detection. Finally, we will discuss reverse-symmetry waveguides, resonant waveguide grating sensors and metal-clad leaky waveguides as alternative signal transducers in optical biosensing.

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Section: Functionalization Of Waveguides For Bioassaysmentioning

confidence: 99%

Section: Functionalization Of Waveguides For Bioassaysmentioning

confidence: 99%

Waveguide-Based Biosensors for Pathogen Detection

Mukundan

Anderson

Grace

et al. 2009

Sensors

169

128

View full text Add to dashboard Cite

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“…The near-total internal reflection in the waveguide provides a strong interaction between the guided light and the surface because a small percentage of the propagated laser light "leaks" out of the waveguide layer creating an evanescent field. The intensity of the evanescent field decays exponentially with distance, with complete loss of intensity at about 200 nm from the waveguide surface [3][4][5]. Therefore, the bulk solution volume is not irradiated while the field intensity at the surface remains strong.…”

Section: Waveguide Assaysmentioning

confidence: 97%

“…Only a few groups have prepared PEG films that simultaneously minimize non-specific interactions and maximize analyte binding for biosensing applications, but each had distinct disadvantages such as non-covalent surface attachment, [13,14] and poorly defined PEG layers [23]. We addressed these concerns by preparing mixed PEG-silane films based on short alkyl chain SAMs and short, discrete PEG chains (3)(4), shown schematically in Figures 1 and 2, for biosensing applications on oxide surfaces [24]. There are several advantages to such a surface for sensing applications, including covalent attachment to the surface, and chemical flexibility.…”

Section: Introductionmentioning

confidence: 99%

“…Our previous work around films for sensing has focused on using phospholipid bilayer membranes supported on a waveguide-based platform. The lipid bilayer architecture has several advantages for biological assays on waveguides, including ease of preparation, low background fluorescence, and excellent specific ligand attachment with suppressed non-specific binding [3][4][5]. However, lipid bilayer membranes cannot endure harsh environmental conditions, such as elevated temperature, washing with detergents/denaturing agents, or passage through an air-water interface.…”

Section: Introductionmentioning

confidence: 99%

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Robust sensing films for pathogen detection and medical diagnostics

et al. 2009

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Our team has developed polyethylene glycol (PEG)-modified, self-assembled monolayers (SAMs) for biological detection on either planar or spherical substrates, which resist non-specific binding while facilitating specific ligand attachment. The preparation and characterization of these thin films, their validation against B. anthracis protective antigen (PA) in a sandwich assay format, and the application of these thin films for quantitative analysis of several medically interesting targets (breast cancer, tuberculosis, and influenza) will be shown.

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Amplification-free nucleic acid detection with a fluorescence-based waveguide biosensor

et al. 2022

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Early detection of pathogens using nucleic acids in clinical samples often requires sensitivity at the single-copy level, which currently necessitates time-consuming and expensive nucleic acid amplification. Here, we describe 1) a redesigned flow cell in the shape of a trapezoid-subtracted geometric stadium, and 2) modified experimental procedures that allow for the measurement of sub-attomolar analytes in microliter quantities on a fluorescence-based waveguide biosensor. We verified our instrumental sensitivity with a 200-μL sample of a fluorescent streptavidin conjugate at 100 zM (100 zeptomolar, or 100·10−21 mol L−1) and theoretically explored the applicability of this modified sensing platform in a sandwich immunoassay format using a Langmuir adsorption model. We present assays that demonstrate specific detection of synthetic influenza A DNA (in buffer) and RNA (in saliva) oligonucleotides at the single-copy level (200 μL at 10 zM) using a fluorescent molecular beacon. Lastly, we demonstrate detection of isolated genomic influenza A RNA at a clinically relevant concentration. This work constitutes a sensitivity improvement of over twelve orders of magnitude compared to our previous nucleic acid detection work, illustrating the significant enhancements that can be gained with optimized experimental design.

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Reagentless optical biosensor

Cited by 4 publications

References 0 publications

Waveguide-Based Biosensors for Pathogen Detection

Waveguide-Based Biosensors for Pathogen Detection

Robust sensing films for pathogen detection and medical diagnostics

Amplification-free nucleic acid detection with a fluorescence-based waveguide biosensor

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