Optical grating coupler biosensors

Vörös, János; Ramsden, Jeremy J.; Csúcs, Gábor; Szendrő, István; Paul, Susan M. De; Textor, Marcus; Spencer, Nicholas D.

doi:10.1016/s0142-9612(02)00103-5

Cited by 386 publications

(165 citation statements)

References 56 publications

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“…This implies that, during the sensing process, the response of the interferometer remains in the linear range. In addition, as pointed out in [6], in first approximation the effective refractive index change of the adlayer is proportional to the change of the adsorbed mass, and to bulk concentration of the analyte. Hence, the initial slope of the signal detected by our interferometric sensor should be proportional to the bulk concentration of the bacteria to be detected.…”

Section: Figurementioning

confidence: 90%

Integrated optical biosensor for rapid detection of bacteria

Mathesz¹,

Valkai²,

Újvárosy³

et al. 2015

Optofluidics, Microfluidics and Nanofluidics

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Abstract:In medical diagnostics, rapid detection of pathogenic bacteria from body fluids is one of the basic issues. Most state-of-the-art methods require optical labeling, increasing the complexity, duration and cost of the analysis. Therefore, there is a strong need for developing selective sensory devices based on label-free techniques, in order to increase the speed, and reduce the cost of detection. In a recent paper, we have shown that an integrated optical Mach-Zehnder interferometer, a highly sensitive all-optical device made of a cheap photopolymer, can be used as a powerful lab-on-a-chip tool for specific, labelfree detection of proteins. By proper modifications of this technique, our interferometric biosensor was combined with a microfluidic system allowing the rapid and specific detection of bacteria from solutions, having the surface of the sensor functionalized by bacterium-specific antibodies. The experiments proved that the biosensor was able to detect Escherichia coli bacteria at concentrations of 10 6 cfu/ml within a few minutes, that makes our device an appropriate tool for fast, label-free detection of bacteria from body fluids such as urine or sputum. On the other hand, possible applications of the device may not be restricted to medical microbiology, since bacterial identification is an important task in microbial forensics, criminal investigations, bio-terrorism threats and in environmental studies, as well.

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Section: Figurementioning

confidence: 90%

Integrated optical biosensor for rapid detection of bacteria

Mathesz¹,

Valkai²,

Újvárosy³

et al. 2015

Optofluidics, Microfluidics and Nanofluidics

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“…The said effects bring about the change of effective refrac− tive indexes of modes propagating in the structure. The changes of effective refractive indexes can be measured by the application of the interferometers of Mach−Zehnder [5][6][7], Young [8,9], Michelson [10] and with a polarimeter [2,11,12] or grating couplers [3,[13][14][15][16][17][18][19][20][21][22]. Due to technologi− cal constraints (the interaction length is limited to single centimetres), the operating range in PEWS is most fre− quently limited to a single interference fringe.…”

Section: Introductionmentioning

confidence: 99%

Optical uniform/gradient waveguide sensor structure - characterization

Karasiński

2011

Opto-Electronics Review

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The paper presents the characterization of a composite uniform/gradient waveguide sensor structure. The results of theoretical analysis and experimental studies have been presented. The influence of sensor structure parameters on homogenous sensitivity and on surface sensitivity has been analyzed. Gradient layers for composite sensor structures were produced using the ion-exchange method, and the uniform layers, using the sol-gel method. In the experimental studies, involving the produced sensor structures, a prism coupler and a grating coupler were applied. Excellent agreement between the results of theoretical analysis and experimental studies has been achieved.

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“…The ability to validate the exact spatial location of immobilised protein and the immobilised quantity thereof on a surface is important and techniques such as surface plasmon resonance [17,18], ellipsometry [19], optical waveguide lightmode spectroscopy [20], and quartz crystal microbalance [21] have been previously reported. These techniques quantitatively measure the amount of protein immobilised on flat, planar surfaces such as glass, gold, and plastic substrates, but these methods cannot easily be utilised for macroporous monolithic materials, because of the huge disparity between the surface area of a monolith compared with a flat surface.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of photografted charged sites within polymer monoliths in capillary columns using contactless conductivity detection

Connolly

O'Shea

Clark

et al. 2007

J of Separation Science

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Original PaperEvaluation of photografted charged sites within polymer monoliths in capillary columns using contactless conductivity detection Capacitively coupled contactless conductivity detection (C 4 D) is presented as a novel and versatile means of visualising discrete zones of charged functional groups grafted onto polymer based monoliths. Monoliths were first formed within 100 lm UV-transparent fused silica capillaries. Photografting methods were subsequently used to graft a charged functional monomer, 2-acrylamido-2-methyl-1-propanesulfonic acid, onto discrete regions of the monolith using a photomask. Post-modification monolith evaluation involves scanning the C 4 D detector along the length of the monolith to obtain a profile of the exact spatial location of grafted charged functionalities with millimetre accuracy. The methodology was extended to the visualisation of several zones of immobilised protein (bovine serum albumin) using photografted azlactone groups to enable covalent attachment of the protein to the monolith at precise locations along its length. In addition, the extent of non-specific binding of protein to the ungrafted regions of the monolith due to hydrophobic interactions could be monitored as an increase in background conductivity of the stationary phase. Finally, the technique was cross-validated using digital photography in combination with a UV light source by immobilising green fluorescent protein in discrete zones and comparing the results obtained using both complementary techniques.

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Optical grating coupler biosensors

Cited by 386 publications

References 56 publications

Integrated optical biosensor for rapid detection of bacteria

Integrated optical biosensor for rapid detection of bacteria

Optical uniform/gradient waveguide sensor structure - characterization

Evaluation of photografted charged sites within polymer monoliths in capillary columns using contactless conductivity detection

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