An immunoassay performed using a microchip electrophoretic system is described. Separation and quantitation of free and bound labeled antigen in a competitive assay are carried out in channels micromachined into fused silica substrates. Such microchips are attractive because of their small size, ruggedness, and amenability to automated handling. The assay achieves the determination of cortisol in blood serum over the range of clinical interest (1-60 micrograms/dL) without the need for extraction or other sample preparation steps. The separation is performed in less than 30 s. Very high throughput is possible by operating the assay in multiple channels in parallel. These characteristics make microchip electrophoretic systems a promising technology for the rapid analysis of clinical samples.

No abstract

No abstract

The Fourier transform infrared/micro-attenuated total reflectance (FT-IR/mATR), X-ray diffraction (XRD), and electronic absorption properties of thin tungsten oxide films are characterized. Thin films of tungsten oxide (100–500 Å) deposited on SiO2 exhibit a different orientation or structure than thicker films. A p-polarized longitudinal optical (LO) mode at 970 cm−1 occurs in all ATR spectra of WO3 thin films and is one of the strongest IR bands in the spectra. The spectroscopic properties of tungsten oxide films are characterized as a function of substrate and heat treatment.

No abstract