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Giammarco J Zdyrko B Petit L Musgraves JD Hu J Agarwal A Kimerling L Richardson K Luzinov I 《Chemical communications (Cambridge, England)》2011,47(32):9104-9106
Polymer multilayered nanocoating capable of concentrating various chemical substances at IR-ATR waveguide surfaces is described. The coating affinity to an analyte played a pivotal role in sensitivity enhancement of the IR-ATR measurements, since the unmodified waveguide did not show any analyte detection. 相似文献
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Laeticia Vurth Caroline Hadad Sylvain Achelle Joaquín C. García-Martinez Julián Rodríguez-López Olivier Stéphan 《Colloid and polymer science》2012,290(14):1353-1359
We report the synthesis of nanosized particles based on bio-compatible polyethylene–polypropylene glycol (pluronic) materials. In aqueous solution, mini-emulsification of pluronic with two pyrimidine chromophores leads to nanoparticles with hydrodynamic radius below 100?nm. We have demonstrated that these probes exhibit a fast and fully reversible solvatochromic behaviour from yellow to purple when decreasing the pH solution. The average acidity constant of both dyes incorporated in pluronic mainly originate from the non-substituted pyrimidine (1,3-diazine) core. The close functionalization of the pyrimidine with pyridyl groups leads to a tridentate ligand suitable for metal cations complexation. Figure
Aqueous nanoparticles of pluronic triblock copolymer incorporating pyrimidine chromophores are sensitive to pH changes: protonation of the dyes within the micelles core occurs in strong acidic aqueous media leading to purple coloration when compared to yellow colour in neutral or basic pH. This solvatochromic behaviour is fully reversible. 相似文献
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Demonstration of chalcogenide glass racetrack microresonators 总被引:1,自引:0,他引:1
We have demonstrated what we believe to be the first chalcogenide glass racetrack microresonator using a complementary metal-oxide semiconductor-compatible lift-off technique with thermally evaporated As(2)S(3) films. The device simultaneously features a small footprint of 0.012 mm x 0.012 mm, a cavity Q (quality factor) of 10,000, and an extinction ratio of 32 dB. These resonators exhibit a very high sensitivity to refractive index changes with a demonstrated detection capability of Dn(As(2)S(3)=(4.5 x 10(-6)+/-10%) refractive index unit. The resonators were applied to derive a photorefractive response of As(2)S(3) to lambda=550 nm light. The resonator devices are a versatile platform for both sensing and glass material property investigation. 相似文献
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Hu J Carlie N Feng NN Petit L Agarwal A Richardson K Kimerling L 《Optics letters》2008,33(21):2500-2502
High-index-contrast compact microdisk resonators in thermally evaporated As2S3 and Ge17Sb12S71 chalcogenide glass films are designed and fabricated using standard UV lithography and characterized. Our pulley coupler configuration demonstrates coupling of the resonators to monolithically integrated photonic wire waveguides without resorting to demanding fine-line lithography. Microdisk resonators in As2S3 support whispering-gallery-mode with cavity quality factors (Q) exceeding 2 x 10(5), the highest Q value reported in resonator structures in chalcogenide glasses to the best of our knowledge. We have successfully demonstrated a lab-on-a-chip prototype sensor device with the integration of our resonator with planar microfluidic systems. The sensor shows a refractive index sensitivity of 182 nm/RIU (refractive index unit) and a wavelength resolution of 0.1 pm through a resonant peak fit. This corresponds to a refractive index detection limit of 8 x 10(-7) RIU at 1550 nm in wavelength, which could be further improved by shifting the operating wavelength to a region where water absorption is reduced. 相似文献
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Dr. Malika Makhlouf Brahmi Dr. Cyril Portmann Danilo D'Ambrosio Dr. Tom M. Woods Damiano Banfi Patrick Reichenbach Laeticia Da Silva Emilie Baudat Dr. Gerardo Turcatti Prof. Dr. Joachim Lingner Prof. Dr. Karl Gademann 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(14):4596-4601
By using the Telospot assay, 27 different extracts of cyanobacteria were evaluated for telomerase inhibition. All extracts showed varying, but significant activity. We selected Microcystis aeruguinosa PCC 7806 to identify the active compound and a bioassay guided fractionation led us to isolate mixtures of sulfoquinovosyl diacylglycerols (SQDGs), which were identified by 2D NMR and MS/MS experiments. Pure SQDG derivatives were then synthesized. The IC50 values of pure synthetic sulfoquinovosyl dipalmitoylglycerol and the monopalmitoylated derivative against telomerase were determined to be 17 and 40 μM , respectively. A structure–activity relationship study allowed the identification of compounds with modified lipophilic acyl groups that display improved activity. 相似文献
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Shanshan Song Nathan Carlie Julie Boudies Laeticia Petit Kathleen Richardson Craig B. Arnold 《Journal of Non》2009,355(45-47):2272-2278
Thin film Ge23Sb7S70 chalcogenide glass has emerged as an important material system for photonic applications due to its high non-linear refractive index. However, one of the challenges is developing low-cost methods to deposit films of glassy material while retaining glass stoichiometry and high film quality. In this paper, we demonstrate a spin-coating technique for the deposition of such films. The dissolution mechanisms of Ge23Sb7S70 in different solvents are studied in order to select the optimal solvent for film deposition. We show that the use of amine-based solvents allow the deposition of stoichiometric films in contrast to alkaline solutions. Films with low surface roughness (RMS roughness <5 nm) and controlled thickness (100–600 nm) can be deposited from solutions. We also show that annealing the films in vacuum decreases the amount of residual solvent, the presence of which is expected to lead to variation in optical properties of the thin films. 相似文献
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