| 1. |
- Alvarez, Jesus, et al.
(författare)
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A Real Time Immunoassay in Alumina Membranes
- 2014
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Ingår i: SENSORS, 2014 IEEE. - : IEEE conference proceedings. ; , s. 1760-1763
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Konferensbidrag (refereegranskat)abstract
- To date, photonic biosensing with porous membranes has produced slow responses and long sensing times, due to the narrow (less than 100 nm) closed end pores of the membranes used. Recently, polarimetry was used to demonstrate analyte flow through, and real time biosensing in, free-standing porous alumina membranes. Here, we demonstrate how an improved functionalization technology, has for the first time enabled a real-time immunoassay within a porous membrane with a total assay time below one hour. With the new approach, we show a noise floor for individual biosensing measurements of 3.7 ng/ml (25 pM), and a bulk refractive index detection limit of 5×10-6 RIU, with a standard deviation of less than 5%. The membranes, with their 200 nm pore diameter enabling targeted delivering of analytes to bioreceptors immobilized on the pore walls, therefore provide a route towards rapid and low cost real-time opto-fluidic biosensors for small sample volumes.
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| 2. |
- Álvarez, Jesús, et al.
(författare)
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Real time optical immunosensing with flow-through porous alumina membranes
- 2014
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier. - 0925-4005 .- 1873-3077. ; 202, s. 834-839
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Tidskriftsartikel (refereegranskat)abstract
- Through the presentation of analytical data from bioassay experiments, measured by polarimetry, we demonstrate for the first time a real time immunoassay within a free standing macroporous alumina membrane. The 200 nm nominal pore diameter of the membrane enables flow-through, thereby providing an ideal fluidic platform for the targeted delivery of analytes to bioreceptors immobilized on the pore walls, enabling fast sensing response times and the use of small sample volumes (<100 μL). For the immunoassay, the pore walls were first coated with the functional copolymer, copoly(DMA-NAS) using a novel coupling process, before immobilization of the allergen protein, β-lactoglobulin, by spotting. The immuno-assay then proceeded with the binding of the primary and secondary antibody cognates, rabbit anti-β-lactoglobulin and anti-rabbit IgG respectively. Through the use of streptavidin coated quantum dots as refractive index signal enhancers, a noise floor for individual measurements of 3.7 ng/mL (25 pM) was obtained, with an overall statistical, or formal assay LOD of 33.7 ng/mL (225 pM), for total assay time below 1 h.
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| 3. |
- Pierer, Jörg, et al.
(författare)
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Photonic sensing of food allergy : integration and miniaturization
- 2012
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Ingår i: Smart Systems Integration.
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Konferensbidrag (refereegranskat)abstract
- Food allergies can provoke severe clinical reactions. Within the FP7 project POSITIVE a Lab-on-a-Chip platform for label-free quantitative allergen testing is under development. The system integrates fluidic handling, optical interrogation and a porous Silicon based bio sensor cartridge. Optical and fluidic concepts have been derived and partially tested with positive results on lab bench level. Further effort has to be spent on higher system integration and miniaturization of the components as well as signal processing and data evaluation. Model tests based on the immobilization of allergens and molecular recognition by specific antibodies have been established proofing the pre-treated porous Silicon membranes bio assay suitability.
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