The collection of saliva is far preferable to collection of blood from the point of view of the person being sampled. However, in recent years microfluidic technologies for measuring analytes in blood have advanced rapidly, while the use of saliva as an analyte has lagged, both in terms of the number of analytes measured and the environments in which such measurements are made. In part, this is because saliva is more variable than plasma, has analytes in lower concentrations, and contains viscous and adhesive mucins. If it were practical to use saliva for many analytes commonly measured in blood, and to make those measurements on several analytes at once, inexpensively, and in a way not requiring technical training, enormous improvements in the quality, frequency and scope of biomedical testing for research, therapy, and health maintenance would be possible, particularly for ambulatory outpatients. This project will develop an integrated microfluidic system for rapidly, inexpensively, and simultaneously measuring multiple analytes in saliva, and in a simple disposable polymeric laminate format. A microfluidic device to allow rapid extraction of analytes from the mucins in saliva will be developed. Two new but demonstrated immunoassay technologies will be coupled to a microfluidic system that allows dry storage of all reagents at ambient conditions and measures multiple analytes in parallel. These assays can measure low levels of hormones, drugs, metabolites, and even proteins that indicate the presence of disease, as well as compounds specific to the oral cavity such as pathogens and markers for oral cancer. The immunoassays will initially be validated on hormones for which commercial immunoassays are available. Ongoing work on development of parallel diffusion immunoassays will be extended to saliva testing through coupling with the mucin-extraction system. To measure analytes present at concentrations below the limit of detection of the diffusion immunoassay, chemically amplified surface plasmon resonance imaging will be used. Dissolution of dry reagent will be employed to decorate the gold surface with multiple capture molecules. Finally, a versatile combined system will be designed and tested that will allow monitoring of samples by the two methods simultaneously. ? ?
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