Ulrich J. Krull

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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)
A CMOS tunable-wavelength multi-color photogate (CPG) sensor is presented. Sensing of a small set of well-separated wavelengths (e.g., > 50 nm apart) is achieved by tuning the spectral response of the device with a bias voltage. The CPG employs the polysilicon gate as an optical filter, which eliminates the need for an external color filter. A prototype has(More)
A spectral-multiplexed fluorescence contact imaging microsystem for DNA analysis is presented. The microsystem integrates a filterless CMOS Color PhotoGate (CPG) sensor that exploits the polysilicon gate as an optical filter, and therefore does not require an external color filter. The CPG is applied to fluorescence-based transduction in a spectrally(More)
Organic fluorophores and quantum dots are ubiquitous as contrast agents for bio-imaging and as labels in bioassays to enable the detection of biological targets and processes. Upconversion nanoparticles (UCNPs) offer a different set of opportunities as labels in bioassays and for bioimaging. UCNPs are excited at near-infrared (NIR) wavelengths where(More)
Semiconductor quantum dots (QDs) have served as the basis for signal development in a variety of biosensing technologies and in applications using bioprobes. The use of QDs as physical platforms to develop biosensors and bioprobes has attracted considerable interest. This is largely due to the unique optical properties of QDs that make them excellent(More)
Issues of water quality are a global problem with potentially devastating results in communities if microbial levels are not monitored and controlled effectively.This is especially true with the potential threat of bioterrorist contamination of water supplies.This study presents a method for quantifying microbial water pathogens by 5' nuclease real-time(More)
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