Zongyuan Chen

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A pneumatically driven, disposable, microfluidic cassette comprised of a polymerase chain reaction (PCR) thermal cycler, an incubation chamber to label PCR amplicons with up-converting phosphor (UPT) reporter particles, conduits, temperature-activated, normally closed hydrogel valves, and a lateral flow strip, was constructed and tested. The hydrogel(More)
An inexpensive, hand-held, point-of-care, disposable, self-contained immunoassay cassette comprised of air pouches for pumping, a metering chamber, reagents storage chambers, a mixer, and a lateral flow strip was designed, constructed, and tested. The assay was carried out in a consecutive flow format. The detection was facilitated with up-converting(More)
An easy to fabricate, thermally-actuated, self-regulated hydrogel valve for flow control in pneumatically driven, microfluidic systems is described. This microvalve takes advantage of the properties of the hydrogel, poly(N-isopropylacrylamide), as well as the aqueous fluid itself to realize flow control. The valve was designed for use in a diagnostic system(More)
The design of a microfluidic lab-on-a-chip system for point-of-care cancer screening and diagnosis of oral squamous cell carcinoma (OSCC) is presented. The chip is based on determining a approximately 30-gene transcription profile in cancer cells isolated from oral fluid samples. Microfluidic cell sorting using magnetic beads functionalized with an antibody(More)
Oral squamous cell carcinoma (OSCC) is a disfiguring and deadly cancer. Despite advances in therapy, many patients continue to face a poor prognosis. Early detection is an important factor in determining the survival of patients with OSCC. No accurate, cost-efficient, and reproducible method exists to screen patients for OSCC. As a result, many patients are(More)
The building blocks for an inexpensive, disposable, luminescence-based microfluidic immunoassay cassette are described, and their integration in a point-of-care diagnostic system is demonstrated. Fluid motion in the cassette is driven by depressing finger-actuated pouches. All reagents needed for the immunoassay can be stored in the cassette in liquid form.(More)
OBJECTIVE We developed a microfluidic system to simultaneously detect host anti-HIV antibodies and viral RNA in the same specimen in order to satisfy two important diagnostic criteria, especially within resource-limited settings. First, the system can detect acute HIV infection and allow immediate confirmation of a seropositive screening result by detection(More)
A "lab-on-a-chip" system for detecting bacterial pathogens in oral fluid samples is described. The system comprises: (1) an oral fluid sample collector; (2) a disposable, plastic microfluidic cassette ("chip") for sample processing including immunochromatographic assay with a nitrocellulose lateral flow strip; (3) a platform that controls the cassette(More)
A self-actuated, flow-cycling polymerase chain reaction (PCR) reactor that takes advantage of buoyancy forces to continuously circulate reagents in a closed loop through various thermal zones has been constructed, tested, and modeled. The heating required for the PCR is advantageously used to induce fluid motion without the need for a pump. Flow velocities(More)
Using polystyrene as a fabrication material and pure acetonitrile as a bonding solvent, we have developed an innovative and inexpensive weak-solvent-based chip lamination process to produce highly functional, completely plastic, microfluidic chips with a 3-layer structure. This simple, scalable and rapid method allows active components, such as multiple(More)