Planar waveguide immunosensor with fluorescent liposome amplification

Choquette, Steven J.; Locascio-Brown, Laurie; Durst, Richard A.

doi:10.1021/ac00025a011

“…For the purposes of this approximation, we did not include the effects of the 0.1 mm thick ITO layer. The calculations for the single mode potassium ion waveguides are somewhat complicated by the gradient index pro®le of these waveguides, since the waveguide thickness varies as a function of the mode [3,23]. However, the thickness of the potassium ion waveguide can be estimated to be approximately 2 mm, for the diffusion conditions and substrates used [3].…”

Section: Evaluation Of Waveguidesmentioning

confidence: 99%

“…A wide variety of inorganic and organic materials have been used to fabricate thin ®lm optical waveguides, and, as a result, planar waveguides can be engineered for speci®c chemical applications. A number of reports depict the use of planar waveguides as attenuation [2],¯uorescence [3], and refractive index [4] sensors for bioachemical measurements, as well as for enhanced Raman spectroscopy [5].…”

Section: Introductionmentioning

confidence: 99%

Electrochemical Modulation of a Waveguide Interferometer

Ramos

¹

,

Nagy

²

,

Choquette

³

2000

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A planar waveguide implementation of a Mach±Zehnder interferometer coated with a thin semiconducting ®lm was fabricated. The semiconducting ®lm was used as an electrode providing a device that can be used as an electrooptic sensor. Changes in the refractive index pro®le occurring in the immediate vicinity of the waveguide surface resulting from a potential scan can be detected by a shift in the interference pattern imaged across the face of a diode array. This report describes the fabrication of the integrated electrooptic device, the electrochemistry and phase response of 7-dimethylamino-1,2-benzophenoxazine (Meldola Blue).

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“…For several years, our research group at NIST and the Durst research group at Cornell University have pioneered the use of liposomes as alternative signal amplification reagents for affinity-based assays [8][9][10][11][12][13]. Liposomes are synthetic cells composed of a phospholipid bilayer membrane that can be made to encapsulate large quantities of detectable molecules including electrochemical and fluorescent tags.…”

Section: Introductionmentioning

confidence: 99%

Liposomes as signal amplification reagents for bioassays in microfluidic channels

Locascio

¹

,

Hong

²

,

Gaitan

³

2002

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Liposomes with encapsulated carboxyfluorescein were used in an affinity-based assay to provide signal amplification for small-volume fluorescence measurements. Microfluidic channels were fabricated by imprinting in a plastic substrate material, poly(ethylene terephthalate glycol) (PETG), using a silicon template imprinting tool. Streptavidin was linked to the surface through biotinylated-protein for effective immobilization with minimal nonspecific adsorption of the liposome reagent. Lipids derivatized with biotin were incorporated into the liposome membrane to make the liposomes reactive for affinity assays. Specific binding of the liposomes to microchannel walls, dependence of binding on incubation time, and nonspecific adsorption of the liposome reagent were evaluated. The results of a competitive assay employing liposomes in the microchannels are presented.

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“…For several years, our research group at NIST and the Durst research group at Cornell University have pioneered the use of liposomes as alternative signal amplification reagents for affinity-based assays [8][9][10][11][12][13]. Liposomes are synthetic cells composed of a phospholipid bilayer membrane that can be made to encapsulate large quantities of detectable molecules including electrochemical and fluorescent tags.…”

Section: Introductionmentioning

confidence: 99%

Liposomes as signal amplification reagents for bioassays in microfluidic channels

Locascio¹,

Hong²,

Gaitan³

2002

View full text Add to dashboard Cite

Liposomes with encapsulated carboxyfluorescein were used in an affinity-based assay to provide signal amplification for small-volume fluorescence measurements. Microfluidic channels were fabricated by imprinting in a plastic substrate material, poly(ethylene terephthalate glycol) (PETG), using a silicon template imprinting tool. Streptavidin was linked to the surface through biotinylated-protein for effective immobilization with minimal nonspecific adsorption of the liposome reagent. Lipids derivatized with biotin were incorporated into the liposome membrane to make the liposomes reactive for affinity assays. Specific binding of the liposomes to microchannel walls, dependence of binding on incubation time, and nonspecific adsorption of the liposome reagent were evaluated. The results of a competitive assay employing liposomes in the microchannels are presented.

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Planar waveguide immunosensor with fluorescent liposome amplification

Cited by 53 publications

References 38 publications

Electrochemical Modulation of a Waveguide Interferometer

Electrochemical Modulation of a Waveguide Interferometer

Liposomes as signal amplification reagents for bioassays in microfluidic channels

Liposomes as signal amplification reagents for bioassays in microfluidic channels

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