The lateral flow test has become the standard bioassay format in low-resource settings because it is rapid, easy to use, and low in cost, uses reagents stored in dry form, and is equipment-free. However, lateral flow tests are often limited to a single chemical delivery step and not capable of the multistep processing characteristic of high performance laboratory-based assays. To address this limitation, we are developing a paper network platform that extends the conventional lateral flow test to two dimensions; this allows incorporation of multistep chemical processing, while still retaining the advantages of conventional lateral flow tests.
View Article and Find Full Text PDFIn many low resource settings multiple diseases are endemic. There is a need for appropriate multi-analyte diagnostics capable of differentiating between diseases that cause similar clinical symptoms. The work presented here was part of a larger effort to develop a microfluidic point-of-care system, the DxBox, for sample-to-result differential diagnosis of infections that present with high rapid-onset fever.
View Article and Find Full Text PDFAs part of an effort to create a point-of-care diagnostic system for the developing world, we present a microfluidic flow-through membrane immunoassay with on-card dry reagent storage. By preserving reagent function, the storage and reconstitution of anhydrous reagents enables the devices to remain viable in challenging, unregulated environmental conditions. The assay takes place on a disposable laminate card containing both a porous membrane patterned with capture molecules and a fibrous pad containing an anhydrous analyte label.
View Article and Find Full Text PDFThis paper describes a general strategy for the fabrication of a microthermocouple based on the spatially defined electroless deposition of metal, followed by annealing and electroplating. We present scanning electron microscopy and atomic force microscopy characterizations of the deposition and annealing process, as well as the performance of the microfabricated Ni-Ag thermocouple. The temperature-voltage curve for this Ni-Ag microthermocouple is linear over the range 0-50 degrees C with a slope of 61.
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