Author:
Daniel Hill
Affiliation:
Universitat de Valencia, Spain
Keyword(s):
Nanophotonics, Slot-Waveguides, Ring Resonators, Porous Silicon, Biosensing, Lab-on-Chip, Birefringence, Quantum Dots.
Related
Ontology
Subjects/Areas/Topics:
Biomedical Optics
;
MEMS and Nanophotonics
;
Mobile Software and Services
;
Optical Materials
;
Optics
;
Organic and Bio-Photonics
;
Photonic and Optoelectronic Materials and Devices
;
Photonics
;
Photonics, Optics and Laser Technology
;
Telecommunications
;
Wireless Information Networks and Systems
Abstract:
For ring resonator based sensors, volumetric limits of detection (LoD) of 510–6 RIU and 8.3x10−6 RIU (refractive index units) for sensitivities of 246nm/RIU and 2169nm/RIU were reported from FP6 SABIO (at 1.31µm) and FP7 InTopSens (at 1.55µm) respectively. These compare well to the state of art of 7.6×10−7 RIU for a sensitivity of 163 nm/RIU, as does the porous alumina based membrane sensors in FP7 Positive with their LoD of 5x10-6 RIU. More interestingly for the membrane sensors, the standard deviation of their measured values was below 5% and their flow through design with lateral distances to the sensor surface less than a diffusion length permit fast response times, short assay times and the use of small sample volumes (< 100 µl). For protein binding recognition, within SABIO a surface LoD of 0.9 pg/mm2 for anti-BSA on a gluteraldehyde-covered surface was recorded, corresponding to a 125ng/ml anti-BSA solution, whilst in InTopSens 5pg/mm2 and 10ng/ml for biotin on a streptavidin
coated surface was seen. For an assay of β-lactoglobulin - anti-β-lactoglobulin - anti-rabbit-IgG –streptavidin conjugated CdSe quantum dots the Positive sensors demonstrated a noise floor for individual measurements of 3.7ng/ml (25pM) for total assay times of under one hour.
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