| e have developed an acoustic immunoassay that couples a mass-amplifying label with a silicon-micromachined gravimetric sensor, the Flexural Plate Wave (FPW) device. This assay has direct application to the diagnostic detection of a breast cancer antigen in the sera of breast cancer patients. The use of an acoustic immunoassay provides an alternative to radioimmunoassay, eliminating the need for radioactive labels that pose health hazards to technicians and require costly disposal.;In this work, we discuss protein immobilization methods and compare methods of attaching proteins to the FPW device surface. We describe a liquid-tight micromachined flow cell package with a 20 ;We also explore methods of providing on-chip sample mixing during protein binding steps. Using the FPW device as an acoustic source, we are able to generate an ultra-sonic form of sample volume agitation that results in faster protein binding. This ability to increase the reaction rate allows us to reduce the total time necessary to perform a measurement to less than a sixth of the time for the original radioimmunoassay. With this reduced assay time, we are still able to detect antigen concentrations at the level of the radioimmunoassay (0.1... |
