Wavelength interrogation of grating-based optical biosensors in the input coupler configuration

Grego, Sonia; McDaniel, Jonathan R.; Stoner, Brian R.

doi:10.1016/j.snb.2007.11.053

Cited by 29 publications

(20 citation statements)

References 34 publications

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“…Therefore, the struc− tures with grating couplers of the high groove density c are frequently preferred. The obtained detection limits involv− ing the change of effective refractive index (DN) min and the refractive index of the cover (Dn c ) min are comparable with the parameters of the commercially available instrument [18], as well as with the parameters of similar structures pre− sented by other authors [1,[35][36][37][38]. In Ref.…”

Section: Detection Limitssupporting

confidence: 76%

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: Detection Limitssupporting

confidence: 76%

Embossable grating couplers for planar evanescent wave sensors

Karasiński

2011

Opto-Electronics Review

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“…The 1 Â 1 mm dimensions for the collection area were chosen to correspond to the minimum size of a typical optical waveguide grating. 6 Each electrode pair is positioned such that the small electrode is the outermost and the large electrode is the innermost feature. When an AC field is induced over the asymmetric pairs, eddies form over the electrodes.…”

Section: Resultsmentioning

confidence: 99%

“…The typical microfluidic devices require cells or other analytes to be physically bound or brought close to the surface of a particular transducer to increase the accuracy of detection. Surface-bound microfluidic devices have been successfully coupled with chemical [1][2][3][4][5] and optical [6][7][8][9][10][11][12][13] transducers to rapidly detect cells and particles in microliter suspensions. However, in order to achieve rapid detection, the time for establishing diffusion equilibrium of the analyte to the transducer should be kept to a minimum, requiring small fluidic chamber heights and, consequently, small sample volumes.…”

Section: Introductionmentioning

confidence: 99%

“…The new configuration is more efficient and compatible with evanescent wave sensing devices. [6][7][8]12,28 We report the characterization of this particle/cell collection device with regard to chamber height, applied potentials, frequency, electrode geometry, electrode and gap width, repetition of asymmetric electrode patterns, and electrolyte concentration. We also introduce techniques combining ACEO with DEP to improve the performance of the device for collecting particles and cells from suspension.…”

Section: Introductionmentioning

confidence: 99%

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On-chip collection of particles and cells by AC electroosmotic pumping and dielectrophoresis using asymmetric microelectrodes

Melvin¹,

Moore²,

Gilchrist³

et al. 2011

Biomicrofluidics

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The recent development of microfluidic "lab on a chip" devices requiring sample sizes <100 lL has given rise to the need to concentrate dilute samples and trap analytes, especially for surface-based detection techniques. We demonstrate a particle collection device capable of concentrating micron-sized particles in a predetermined area by combining AC electroosmosis (ACEO) and dielectrophoresis (DEP). The planar asymmetric electrode pattern uses ACEO pumping to induce equal, quadrilateral flow directed towards a stagnant region in the center of the device. A number of system parameters affecting particle collection efficiency were investigated including electrode and gap width, chamber height, applied potential and frequency, and number of repeating electrode pairs and electrode geometry. The robustness of the on-chip collection design was evaluated against varying electrolyte concentrations, particle types, and particle sizes. These devices are amenable to integration with a variety of detection techniques such as optical evanescent waveguide sensing.

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“…However, many refractometers have in-built temperature compensation -either scale or additional optical wedge are mounted on the bimetallic strip [9]. The soluble solids and ascorbic acid are primarily sugars; sucrose, fructose, and glucose.…”

Section: Introductionmentioning

confidence: 99%

Design, fabrication and performance evaluation of a portable hand-held refractometer

et al. 2018

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Refractometer is a simple optical instrument that measures the amount of light refracted in a liquid. It measures on a "Brix" scale and the Brix level determines the flavor and quality of fruits and vegetables. The fabricated refractometer has built-in temperature compensations for Brix measurements and it is only valid for fruit juices solutions The refractometer is equipped with a thermometer and there is a means of circulating water through the refractometer to maintain a given temperature The designed refractometer consists of a light source, filtered to a single wavelength, which is directed towards the prism-sample interface by a converging lens. This creates a range of incidence angles, some of which will be completely reflected. A Charge-coupled Device (CCD) sensor precisely measures the intensity of the reflected light and determines the exact angle at which light begins to be completely reflected. The fabricated refractomter consists of six main parts which include focus adjustment, calibration screw, daylight plate, eye piece, rubber grip and main prism assembly. Actual tests were conducted using samples of orange, pineapple and cashew juices at certain levels of pH values. The average percentage Brix values of orange, cashew and pineapple juices are 7.88%, 10.84% and 6.91% respectively. It was observed that cashew juice has highest percentage Brix followed by orange and pineapple juices. This implies that cashew juice can deteriorate faster than the other two juices. The analysis of variance (ANOVA) for the effect of temperature and pH used for the experiment show that F-calculated (4.248) is greater than F-table (3.35) at 5% probability level; therefore, the pH of fruit juice has an effect on its brix value. It appears that the rate of pH or temperature sensitivity of the fabricated refractometer used could not be the actual or maximum rate for the experiment

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Wavelength interrogation of grating-based optical biosensors in the input coupler configuration

Cited by 29 publications

References 34 publications

Embossable grating couplers for planar evanescent wave sensors

Embossable grating couplers for planar evanescent wave sensors

On-chip collection of particles and cells by AC electroosmotic pumping and dielectrophoresis using asymmetric microelectrodes

Design, fabrication and performance evaluation of a portable hand-held refractometer

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