Learn More
The protozoan pathogens Giardia lamblia and Cryptosporidium parvum are major causes of waterborne enteric disease throughout the world. Improved detection methods that are very sensitive and rapid are urgently needed. This is especially the case for analysis of environmental water samples in which the densities of Giardia and Cryptosporidium are very low.(More)
The marriage of microfluidics with detection technologies that rely on highly selective nucleic acid hybridization will provide improvements in bioanalytical methods for purposes such as detection of pathogens or mutations and drug screening. The capability to deliver samples in a controlled manner across a two-dimensional hybridization detection platform(More)
Single-stranded deoxyribonucleic acid (ssDNA) thymidylic acid icosanucleotides (dT20) were synthesized on the surfaces of derivatized quartz optical fibers to create an optical DNA biosensor. The synthesis made use of an automated solid-phase synthesizer and phosphoramidite synthons. The covalently immobilized oligomers were found to hybridize with(More)
Localized surface plasmon resonance (LSPR) is an optical phenomena generated by light when it interacts with conductive nanoparticles (NPs) that are smaller than the incident wavelength. As in surface plasmon resonance, the electric field of incident light can be deposited to collectively excite electrons of a conduction band, with the result being coherent(More)
Capillary thin layer and gas chromatographic methods for analysis of the extent of oxidation in phosphatidyl choline/cholesterol samples are described. Examples of systems suitable for qualitative and quantitative analysis, based on use of unmodified samples or of their derivatives, are illustrated. A method for concurrent quantitative determination of(More)
The spectroscopic properties of CdSe/ZnS quantum dots (QDs) were observed to change as a function of thioalkyl acid ligand. Experiments were performed using 2, 3, 6, and 11-carbon linear thioalkyl acids, as well as mercaptosuccinic acid (MSA) and dihydrolipoic acid (DHLA). Bathochromic shifts of up to 14 nm in the emission spectra of QDs capped with these(More)
Contamination of food and water supplies by microorganisms such as Escherichia coli, the need for point-of-care bedside analysis of biological samples, and concerns about terrorist attacks using biological organisms, have made the development of fast, reliable, and sensitive analytical methodologies for use in monitoring of pathogens very important. With a(More)
AIMS 5'-Nuclease (real-time, quantitative) PCR methodologies were developed and applied as diagnostic tools for the detection of microcystin-producing cyanobacteria and Escherichia coli in water. METHODS AND RESULTS PCR was used to detect regions of the lacZ gene in E. coli, and the microcystin synthetase gene in microcystin-producing cyanobacteria. In(More)
In this work, we describe and implement an electrokinetic approach for single-nucleotide polymorphism (SNP) discrimination using a PDMS/glass-based microfluidic chip. The technique takes advantage of precise control of the coupled thermal (Joule heating), shear (electroosmosis), and electrical (electrophoresis) energies present at an array of probes(More)
Surface plasmon microscopy is applied to monolayers of dimyristoylphosphatidylethanolamine, dipcast at high lateral pressure (35 mN/m) on a solid substrate. The vertical resolution of better than 1 nm and an in-plane resolution of-10 pm allow for the detection of two separate solid domains. Assuming a fixed value for the lipid refractive index, the tilt(More)