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Optics Express Oct 2010A comprehensive investigation of real-time temperature-induced resonance shift cancellation for silicon wire based biosensor arrays is reported for the first time. A...
A comprehensive investigation of real-time temperature-induced resonance shift cancellation for silicon wire based biosensor arrays is reported for the first time. A reference resonator, protected by either a SU8 or SiO(2) cladding layer, is used to track temperature changes. The temperature dependence of resonators in aqueous solutions, pertinent to biosensing applications, is measured under steady-state conditions and the operating parameters influencing these properties are discussed. Real-time measurements show that the reference resonator resonances reflect the temperature changes without noticeable time delay, enabling effective cancellation of temperature-induced shifts. Binding between complementary IgG protein pairs is monitored over 4 orders of magnitude dynamic range down to a concentration of 20 pM, demonstrating a resolvable mass of 40 attograms. Reactions are measured over time periods as long as 3 hours with high stability, showing a scatter corresponding to a fluid refractive index fluctuation of ± 4 × 10(-6) in the baseline data. Sensor arrays with a SU8 protective cladding are easy to fabricate, while oxide cladding is found to provide superior stability for measurements involving long time scales.
Topics: Animals; Biosensing Techniques; Electricity; Immunoglobulin G; Rabbits; Silicon; Silicon Dioxide; Spectrum Analysis; Staining and Labeling; Temperature; Time Factors
PubMed: 21164626
DOI: 10.1364/OE.18.022867 -
Optics Express Feb 2008In this paper we introduce Nanoscale Optofluidic Sensor Arrays (NOSAs), which are an optofluidic architecture for performing highly parallel, label free detection of...
In this paper we introduce Nanoscale Optofluidic Sensor Arrays (NOSAs), which are an optofluidic architecture for performing highly parallel, label free detection of biomolecular interactions in aqueous environments. The architecture is based on the use of arrays of 1D photonic crystal resonators which are evanescently coupled to a single bus waveguide. Each resonator has a slightly different cavity spacing and is shown to independently shift its resonant peak in response to changes in refractive index in the region surrounding its cavity. We demonstrate through numerical simulation that by confining biomolecular binding to this region, limits of detection on the order of tens of attograms (ag) are possible. Experimental results demonstrate a refractive index (RI) detection limit of 7 x 10(-5) for this device. While other techniques such as SPR possess a equivalent RI detection limit, the advantage of this architecture lies in its potential for low mass limit of detection which is enabled by confining the size of the probed surface area.
Topics: Equipment Design; Equipment Failure Analysis; Microarray Analysis; Microfluidic Analytical Techniques; Nanotechnology; Optics and Photonics; Refractometry; Transducers
PubMed: 18542241
DOI: 10.1364/oe.16.001623 -
Lab on a Chip Jul 2012We experimentally demonstrate a method to create large-scale chip-integrated photonic crystal sensor microarrays by combining the optical power splitting characteristics...
We experimentally demonstrate a method to create large-scale chip-integrated photonic crystal sensor microarrays by combining the optical power splitting characteristics of multi-mode interference (MMI) power splitters and transmission drop resonance characteristics of multiple photonic crystal microcavities arrayed along the length of the same photonic crystal waveguide. L13 photonic crystal microcavities are employed which show high Q values (~9300) in the bio-ambient phosphate buffered saline (PBS) as well as high sensitivity, experimentally demonstrated to ~98 atto-grams. Two different probe antibodies were specifically detected simultaneously with a control sample, in the same experiment.
Topics: Animals; Antibodies; Biosensing Techniques; Crystallization; Goats; Humans; Immunoglobulin G; Interleukin-10; Photons; Protein Array Analysis; Rabbits; Rats; Silicon
PubMed: 22522742
DOI: 10.1039/c2lc40081b