Amorphous silicon based p–i–i–n photodetector detects 12 nm thin protein layers

Sämann, Marc; Steinle, Lutz; Schubert, M.B.

doi:10.1016/j.jnoncrysol.2007.09.041

Cited by 5 publications

(3 citation statements)

References 6 publications

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“…Avoiding the large and optically inconvenient microtiter plate format and using an object lens, a quantitative imaging system is achieved with approximately 700 spots cm −2 and noise representing less than 10 pm thickness incertainty which is equivalent to 2-5 pg mm −2 of biomaterial [192]. Latest developments focus on wavelength-selective detection using a multilayer semiconductor system, where the chip may be disposable in the future and which allows measurements at four wavelengths [193]. Such systems are planned to be used in point of care testing [194a].…”

Section: Various Realizationsmentioning

confidence: 99%

Direct Optical Detection in Bioanalytics

Gauglitz¹,

Goddard²

2014

Handbook of Spectroscopy

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Section: Various Realizationsmentioning

confidence: 99%

Direct Optical Detection in Bioanalytics

Gauglitz¹,

Goddard²

2014

Handbook of Spectroscopy

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“…48 Also, a-Si:H p-i-i-n photodiodes have been used to detect the growth of thin protein layers by reflectrometric interference spectroscopy. 49 Other applications of a-Si:H photodiodes in biosensing include chemiluminescent and colorimetric detection in immunoassays using reaction volumes in the 10-50 L range. [50][51][52] Preliminary results have also been reported combining colorimetric detection with a-Si:H photodiodes and microfluidic immunoassays.…”

Section: Introductionmentioning

confidence: 99%

Heterogeneous immunoassays in microfluidic format using fluorescence detection with integrated amorphous silicon photodiodes

et al. 2011

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Miniaturization of immunoassays through microfluidic technology has the potential to decrease the time and the quantity of reactants required for analysis, together with the potential of achieving multiplexing and portability. A lab-on-chip system incorporating a thin-film amorphous silicon (a-Si:H) photodiode microfabricated on a glass substrate with a thin-film amorphous silicon-carbon alloy directly deposited above the photodiode and acting as a fluorescence filter is integrated with a polydimethylsiloxane-based microfluidic network for the direct detection of antibody-antigen molecular recognition reactions using fluorescence. The model immunoassay used consists of primary antibody adsorption to the microchannel walls followed by its recognition by a secondary antibody labeled with a fluorescent quantum-dot tag. The conditions for the flow-through analysis in the microfluidic format were defined and the total assay time was 30 min. Specific molecular recognition was quantitatively detected. The measurements made with the a-Si:H photodiode are consistent with that obtained with a fluorescence microscope and both show a linear dependence on the antibody concentration in the nanomolar-micromolar range.

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“…These spectrally selective photodetectors have the ability to replacing the so far needed spectrometer. Current/voltage characteristics and the spectral selectivity are already published in [3]. The use of amorphous silicon carbide in the p-type and the first intrinsic layer enhances the sensitivity through very low dark currents of the photodetectors and enables the adjustment of the absorption characteristics.…”

mentioning

confidence: 99%

Amorphous silicon based p‐i‐i‐n photodetectors for point‐of‐care testing

Sämann¹,

Furin

Thielmann

et al. 2010

Phys. Status Solidi (c)

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Modern medical diagnostics demands point‐of‐care testing (POCT) systems for quick tests in clinical or out‐patient environments. This investigation combines the Reflectometric Interference Spectroscopy (RIfS) with thin film technology for a highly sensitive, direct optical and label‐free detection of proteins, e.g. inflammation or cardiovascular markers. Amorphous silicon (a‐Si) based thin film photodetectors replace the so far needed spectrometer and permit downsizing of the POCT system. Photodetectors with p‐i‐i‐n structure adjust their spectral sensitivity according to the applied read‐out voltage. The use of amorphous silicon carbide in the p‐type and the first intrinsic layer enhances the sensitivity through very low dark currents of the photodetectors and enables the adjustment of their absorption characteristics. Integrating the thin film photodetectors on the rear side of the RIfS substrate eliminates optical losses and distortions, as compared to the standard RIfS setup. An integrated Application Specific Integrated Circuit (ASIC) chip performs a current‐frequency conversion to accurately detect the photocurrent of up to eight parallel photodetector channels. In addition to the optimization of the photo‐detectors, this contribution presents first successful direct optical and label‐free RIfS measurements of C‐reactive protein (CRP) and D‐dimer in buffer solution in physiological relevant concentrations. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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Amorphous silicon based p–i–i–n photodetector detects 12 nm thin protein layers

Cited by 5 publications

References 6 publications

Direct Optical Detection in Bioanalytics

Direct Optical Detection in Bioanalytics

Heterogeneous immunoassays in microfluidic format using fluorescence detection with integrated amorphous silicon photodiodes

Amorphous silicon based p‐i‐i‐n photodetectors for point‐of‐care testing

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