Ulrich J. Krull

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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 potential for a simultaneous two-colour diagnostic scheme for nucleic acids operating on the basis of fluorescence resonance energy transfer (FRET) has been demonstrated. Upon ultraviolet excitation, two-colours of CdSe/ZnS quantum dots with conjugated oligonucleotide probes act as energy donors yielding FRET-sensitized acceptor emission upon(More)
A comprehensive review of the development of assays, bioprobes, and biosensors using quantum dots (QDs) as integrated components is presented. In contrast to a QD that is selectively introduced as a label, an integrated QD is one that is present in a system throughout a bioanalysis, and simultaneously has a role in transduction and as a scaffold for(More)
Quantum dots (QDs) have a number of unique optical properties that are advantageous in the development of bioanalyses based on fluorescence resonance energy transfer (FRET). Researchers have used QDs as energy donors in FRET schemes for the analysis of nucleic acids, proteins, proteases, haptens, and other small molecules. This paper reviews these(More)
Silane coupling agents are commonly used to activate surfaces for subsequent immobilization of biomolecules. The homogeneity and surface morphology of silane films is important for controlling the structural order of immobilized single-stranded DNA probes based on oligonucleotides. The surfaces of silicon wafers and glass slides with covalently attached(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)
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)
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)
Paper-based diagnostic assays are gaining increasing popularity for their potential application in resource-limited settings and for point-of-care screening. Achievement of high sensitivity with precision and accuracy can be challenging when using paper substrates. Herein, we implement the red-green-blue color palette of a digital camera for quantitative(More)
Solid-phase assays using immobilized quantum dots (QDs) as donors in fluorescence resonance energy transfer (FRET) have been developed for the selective detection of nucleic acids. QDs were immobilized on optical fibers and conjugated with probe oligonucleotides. Hybridization with acceptor labeled target oligonucleotides generated FRET-sensitized acceptor(More)