The effect of three-dimensional confinement on the size and morphology of a vesicular surfactant mesophase obtained by mixing micellar solutions of cetyltrimethylammonium bromide and dodecylbenzenesulfonic acid has been studied using small-angle neutron scattering (SANS). The confined spaces were generated by the random close packing of polystyrene beads of radius Rb=1.5, 0.25, and 0.1 microm, ...

In this contribution we present the principle and measurement results on cytometric detection of single biological cells using integrated photodiodes. The sensing element is built into a microfluidic flow cell that allows for positioning the cells directly over the sensor. Additionally to results with calibrated polystyrene beads we show sensor readings for yeast cells. Experiments show that th...

We present the characterization of short-range ordered hexagonal arrays of subwavelength holes in thin gold films. The hole arrays are fabricated by a low-cost technique using convectively self-assembled polystyrene beads as an initial pattern template. Our results suggest that corrugated, short-range ordered hole arrays allow the excitation of resonant surface plasmons. This opens the door to ...

I describe the use of latex agglutination as a simple readout for DNA hybridization assays. Latex agglutina-tion is a well-known readout for antibody-based diagnos-tics (1, 2) and uses " sandwich " assay chemistry for which analogous DNA assays are well known (3, 4). Latex agglutination is extremely simple and chemically robust, and latex particles have been used as a label in DNA hybridization...

We report the first experimental observation of momentum transfer from a surface plasmon to a single dielectric sphere. Using a photonic force microscope, we measure the plasmon radiation forces on different polystyrene beads as a function of their distance from the metal surface. We show that the force magnitude at resonance is strongly enhanced compared to a nonresonant illumination. Measurem...

Commercial 125I anti-HBs was processed to yield a sixfold improvement in economy without significant loss of sensitivity or specificity. Additional polystyrene beads were coupled with commercially supplied anti-HBs. The modified assay (Mod-RIA) was compared with commercial RIA, EIA, and RPHA using established HBsAg panels. Mod-RIA was also compared with HEPATEST (RPHA) for screening 71 200 fres...

A facile homogenous precipitation method has been developed for the synthesis of multifunctional, magnetic, luminescent nanocomposites with Fe(3)O(4) nanoparticles as the core and europium-doped yttrium oxide (Y(2)O(3):Eu) as the shell. The nanocomposites showed both super-paramagnetic behavior and unique europium fluorescence properties with high emission intensity. Their surface has been modi...