Reference pads for miniature integrated optical sensors

Dübendorfer, J.; Kunz, R.

doi:10.1016/s0925-4005(97)80180-3

Cited by 14 publications

(6 citation statements)

References 16 publications

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“…In some cases as, e.g., in gas chemical sensors, the drift affected by the change of the refractive index of wave− guide film can be controlled by the application of a refer− ence path. Such a solution is particularly grounded due to a simultaneous correction of the influence of temperature on sensor structure parameters [42]. In the measurements of the refractive index of liquids, the achievement of low detection limit of the refractive index (Dn c ) min offered by the measure− ment setup requires that the temperature stabilization should be applied.…”

Section: Discussionmentioning

confidence: 99%

“…In the measurements of the refractive index of liquids, the achievement of low detection limit of the refractive index (Dn c ) min offered by the measure− ment setup requires that the temperature stabilization should be applied. The thermo−optical coefficient of water is ( ¶n c / ¶T) H 2 O = -110.6´10 -6 RIU×K -1 [42]. It means that the influence of temperature on the refractive index of water, when investigating water solutions (n c~1 .33), makes it im− possible to apply high sensitivities which are offered by sen− sor structures based on tantalum pentoxide waveguides and titania waveguides.…”

Section: Discussionmentioning

confidence: 99%

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Embossable grating couplers for planar evanescent wave sensors

Karasiński

2011

Opto-Electronics Review

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The paper presents input grating couplers to be applied in planar evanescent wave sensors. Waveguide films SiO2:TiO2 were obtained using the sol-gel method, and grating couplers with a groove density of 1000 g/mm and 2400 g/mm were produced using the method of master grating embossing in sol film. The influence of refractive index of the cover on incoupling angles was presented. Basing on the experimental results, detection limits involving the changes of effective indexes and refractive indexes of the cover for the investigated planar structures were determined. Sensor structures with the couplers having a groove density of 1000 g/mm enable to detect minimum changes of the effective index below 3.3×10−7 and to detect minimum changes of refractive index of the cover below 2.3×10−6. Detection limits for the structures with couplers having the groove density of 2400 g/mm are over twofold higher.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Embossable grating couplers for planar evanescent wave sensors

Karasiński

2011

Opto-Electronics Review

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“…One of the first example of on-chip optical sensor with multiple sensing regions was presented in the study of Dubendorfer et al (1997). This system contributed to increase the level of automation and integration in the design of self-sufficient microfluidic platforms.…”

Section: Introductionmentioning

confidence: 99%

A polymeric micro-optical system for the spatial monitoring in two-phase microfluidics

Sapuppo

Schembri

Fortuna

et al. 2011

Microfluid Nanofluid

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This article presents a polymeric micro-optical system that consists of two coupled miniaturized devices for spatially distributed characterization of microfluidic two-phase phenomena exploiting multiwavelength optical signals. The input device implements four optical windows (slits) which are superimposed on the centerline of a microfluidic serpentine channel and illuminate specific locations of the microchannel. The flow-related information is then collected by an ad hoc polymeric micro-optical output device that guides and merges the spatially distributed information into a single output signal, which maintains memory of the spatial coordinates by using the wavelengths as fingerprints of the slits' position in the microfluidic channel. Both micro-optical devices were designed, simulated, and characterized in static and dynamic conditions. Experiments on two-phase (air and ethanol) flow were carried out by applying constant and periodic flow rate functions. In both cases, the system was proved to be efficient in capturing the spatial-temporal dynamics of flow profiles.

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“…These sensors rely on fluorescence of the tagged molecules detected using confocal microscopes and sensitive photo-detectors, but the low intensity of fluorescent radiation requires long integration times, which limit the through-put of the sensor. Even in the case of sensors developed on the basis of interferometry, as in the case of waveguides and grating couplers [3][4][5][6], the static structures prevent repeatitive scanning and thus lack high-speed capabilities. We have introduced previously the use of spinning-disk interferometry implemented in a bio-optical compact-disk (BioCD) format for highspeed, label-free, direct detection of antibody-antigen binding with high data sampling rates of up to 100 kHz [7].…”

Section: Introductionmentioning

confidence: 99%

Label-free multi-analyte detection using a BioCD

et al. 2005

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We previously reported the application of spinning-disk interferometry, implemented in a compact optical sensor format called the BioCD, in the detection of antigen-antibody recognition. The BioCD consists of interferometers micro-fabricated on the surface of a 2" laser mirror disk, which can spin up to 6000 rpm resulting in high data acquisition rates. The interferometric elements are fabricated by evaporating gold ridges on the mirror substrate operating in the linear sensitivity regime of the interferometer defined as quadrature. Antibodies or proteins are immobilized on the gold interferometric structures through alkanethiols, and the target molecules are immobilized by application of reagents or samples to the disk while it is spinning. The centrifugal force distributes the sample over the sensor surface, causing a change in the optical phase of the interferometric elements, which is detected in real time using a lock-in amplifier with small detection bandwidth. We detected the binding of Mouse IgG by immobilized AntiMouse IgG using the BioCD with a detection limit of 1 ng/ml and low non-specific binding. Furthermore, the selectivity of specific binding was found to be greater than 1 in 10000, determined using the response curve of the BioCD to exposures of specific and non-specific analytes of varying concentrations. This opens up the possibility of simultaneous detection of several analytes with the same sensor while maintaining high selectivity. In this paper we demonstrate simultaneous detection of Rabbit and Mouse IgG on the same disk. The sensitivity limit for multi-analyte detection remains the same as that for a single analyte. In addition to the ability to do simultaneous detection, the current detection scheme presents a way to reference the results of one track with respect to others, thus increasing the reliability of the data. Used in conjunction with high-density protein patterning techniques, the BioCD has the potential to be a highly multiplexed label-free high-speed sensor.

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Reference pads for miniature integrated optical sensors

Cited by 14 publications

References 16 publications

Embossable grating couplers for planar evanescent wave sensors

Embossable grating couplers for planar evanescent wave sensors

A polymeric micro-optical system for the spatial monitoring in two-phase microfluidics

Label-free multi-analyte detection using a BioCD

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