Crystallization multiplexed

The concept is demonstrated for a simultaneous immunoassay of (32-microglobulin, IgG, bovine serum albumin, and C-reactive protein in connection with ZnS, CdS, PbS, and CuS colloidal crystals, respectively (Fig. 14.6). These nanocrystal labels exhibit similar sensitivity. Such electrochemical coding could be readily multiplexed and scaled up in multiwell microtiter plates to allow simultaneous parallel detection of numerous proteins or samples and is expected to open new opportunities for protein diagnostics and biosecurity. 

Fig. 16.2 Nanoscale optofluidic sensor arrays (NOSA). (a) 3D illustration of a NOSA sensing element. It consists of a ID photonic crystal microcavity, which is evanescently coupled to a Si waveguide, (b) The electric field profile for the fundamental TE mode propagating through an air clad Si waveguide on SiOi. (c) SEM of a NOSA device array. It illustrates how this architecture is capable of two dimensional multiplexing, thus affording a large degree of parallelism, (d) Actual NOSA chip with an aligned PDMS fluidic layer on top. Reprinted from Ref. 37 with permission. 2008 Optical Society of America...

It is often desirable to immobilize different biomolecules on different sensing elements in close proximity on the same nanophotonic sensor in the development of a multiplexed sensor. This is the case in the example of parallel ID photonic crystal resonators described in Sect. 16.4. Cross-contamination of biomolecules must be avoided in order to preserve high specificity. We have found that a combination of parylene biopatteming and polydimethylsiloxane (PDMS) microfluidics is a convenient means to immobilized multiple biomolecules in close proximity without cross-contamination as shown in Fig. 16.8. Parylene biopatteming is first used to expose only the regions of highest optical intensity of the nanosensor for functionalization. Second, a set of PDMS microfluidics is applied to the parylene-pattemed nanophotonic sensor, and the biomolecules to be attached... 

Fig. 16.8 Multiplexing immobilization on paralell resonators, (a) SEM of parallel resonators (scale bar is 3 pm), (b) SEM of parallel parylene patterned ID photonic crystal resonators (scale bar is 20 pm), (c) Fluorescence micrograph of patterned capture prohes after parylene removal (scale bar is 20 pm)...

It can be safely predicted that applications of liquid crystals will expand in the future to more and more sophisticated areas of electronics. Potential applications of ferroelectric liquid crystals (e.g. fast shutters, complex multiplexed displays) are particularly exciting. The only LC that can show ferroelectric property is the chiral smectic C. Viable ferroelectric displays have however not yet materialized. Antifer-roelectric phases may also have good potential in display applications. Supertwisted nematic displays of twist artgles of around 240° and materials with low viscosity which respond relatively fast, have found considerable application. Another development is the polymer dispersed liquid crystal display in which small nematic droplets ( 2 gm in diameter) are formed in a polymer matrix. Liquid crystalline elastomers with novel physical properties would have many applications. 

Nal(Tl) crystals. The sample to be counted is mounted between Mylar sheets on a 1/4-inch thick X 5-inch diameter plastic ring. This system is presently used with a four quadrant, multiplexed, 4096-channel, multidimensional analyzer. The multidimensional y spectrum in coincidence with the proportional counter events is recorded in one quadrant, and the anticoincident multidimensional y spectrum is recorded in another quadrant thus, no data are lost. The various background y spectra obtained with this detector assembly are compared in Figure 12. The y-y coinci-... 

The requirement of a very high and constant resistivity over time of nematic mixtures for TN-LCDs with active matrix addressing meant that new liquid crystals which met this and the other specifications, such as low viscosity and high positive dielectric anisotropy, were needed. The nitriles used in nematic mixtures for TN-LCDs with direct or multiplex addressing were soon found to be unsuitable for TN-LCDs with active matrix addressing. The polar nature of the cyano group leads to the solvation of ions from some of the layers on the... 

Apolar nematic compounds usually possess a low k2,-ilk ratio e.g. 1.0 < 33/ < 1.5), partially due to the absence of molecular dimers. However, they are still essential components of nematic mixtures for STN-LCDs, since they are used to lower the viscosity and melting point of a nematic mixture of polar components as well as improve the multiplexability of the mixture due in part to the reduction in the proportion of molecular dimers of associated polar molecules. Therefore, the synthesis of the first polar alkenyl liquid crystals with high k jku ratios led to the synthesis of a series of apolar alkenyl-substituted compounds with the carbon-carbon double bond in various positions in the terminal chain. Some typical compounds (140-149) are shown in Table... 

Division Multiplexer) in optical communication areas. YVO4 crystal doped with Nd " ion was a promising crystal for its low threshold and large laser emission cross section [2-4]. In this paper synchrotron radiation X-ray topograph and Electronic Probe Microscope Analysis were utilized to investigate the defects of YVO4 crystal. 

Suzuki, K., Kubota, H., Kawanishi, S. et al., High-speed bi-directional polarisation division multiplexed optical transmission in ultra low-loss (1.3 dB/km) polarisation-maintaining photonic crystal fibre, Electron. Lett., 37, 1399, 2001. 

Figure 1. Current Nanoscale Optofluidic Sensor Arrays, (a) 3D rendering of the NOSA device, (b) 3D rendering after association of the corresponding antibody to the antigen immobilized resonator, (c) Experimental data illustrating the successful detection of 45 pg/ml of anti-streptavidin antibody. The blue trace shows the initial baseline spectrum corresponding to Fig. la where the first resonator is immobilized with streptavidin. The red trace shows the test spectra after the association of anti-streptavidin. (d) Finite difference time domain (FDTD) simulation of the steady state electric field distribution within the 1-D photonic crystal resonator at the resonant wavelength, (e) SEM image demonstrating the two-dimensional multiplexing capability of the NOSA architecture.

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