A simple, new aptamer-photonic crystal encoded suspension array was designed to simultaneously quantify and qualify ochratoxin A(OTA) and fumonisin B1(FB1) in cereal samples. The aptamers of OTA and FB1 were immobilized on the surfaces of photonic crystals by chemical bonding. When the target mycotoxins appear in a sample, the fluorescence-labeled complementary DNA of the aptamer dissociates fr...

Protein ligands were conjugated to the surface of biodegradable microspheres. These microsphere-ligand conjugates were then used in two in vitro model systems to evaluate the effect of conjugated ligands on microsphere behavior. Microsphere retention in agarose columns was increased by ligands on the microsphere surface specific for receptors on the agarose matrix. In another experiment, conjug...

The detection of electric field by monitoring the optical whispering gallery mode shifts of polymeric microspheres is demonstrated. Two types of spheres are considered; (i) a polydimethylsiloxane (PDMS) sphere with 60 parts base silicon elastomer-to-1 part polymer curing agent by volume and; (ii) a silica sphere coated with a PDMS (uncured) base. The optical mode shifts are caused by perturbati...

The effect of hydrostatic pressure on solid and hollow microsphere optical resonators was investigated. The primary goal was to explore the feasibility of a micro-optical pressure sensor based on whispering gallery modes (WGMs) and to quantify the deleterious effect of environmental pressure changes on other WGM-based sensors. Expressions were developed for WGM shifts due to changes in hydrosta...

Temperature measurement utilizing Whispering Gallery Modes (WGM) in silica microspheres is analytically and experimentally studied over a wide range of temperature, cryogenic (~110K) to above room temperatures (310K). Experimental results using a resonance wavelength shift technique show excellent sensitivity and repeatability for point temperature measurements as well as the capability for ult...