PNNL

Abstract

This paper will provide an overview of the renewable surface biosensor research at Pacific Northwest National Laboratory (PNNL) in Richland, Washington. One major challenge in the development of biosensors is the limited lifetime of a chemically selective surface that includes biomolecules. Renewable surface biosensors address this issue by using fresh aliquots of derivatized microbeads for each analysis. The analyte detection can then occur on the microbeads, or downstream from the microbeads. The volume of beads used for each analysis is typically only about 1 microliter, so these microsensor systems can be small in size and require small amounts of reagents. The chemistry on the surface of the microbeads is tailored for applications such as protein (e.g. antibody) and DNA-based detection, and the beads themselves can be polymer or ceramic microspheres ranging from 5 to 150 microns in diameter, or superparamagnetic particles ranging from only 50 nanometers to several microns in size. Since renewable surface microfluidic systems can handle fluid volumes ranging from many milliliters down to microliters, they are ideal for analyte concentration and purification from "real-world" samples for delivery to microsensors and nanosensors.