title: Single bead-based electrochemical biosensor.
abstract: A simple, robust, single bead-based electrochemical biosensor was fabricated and characterized. The sensor's working electrode consists of an electrochemically etched platinum wire, with a nominal diameter of 25 microm, hermetically heat-fusion sealed in a pulled glass capillary (micropipette). The sealing process does not require any epoxy or glue. A commercially available, densely functionalized agarose bead was mounted on the tip of the etched platinum wire. The use of a pre-functionalized bead eliminates the tedious and complicated surface functionalization process that is often the bottleneck in the development of electrochemical biosensors. We report on the use of a biotin agarose bead-based, micropipette, electrochemical (Bio-BMP) biosensor to monitor H(2)O(2) concentration and the use of a streptavidin bead-based, micropipette, electrochemical (SA-BMP) biosensor to detect DNA amplicons. The Bio-BMP biosensor's response increased linearly as the H(2)O(2) concentration increased in the range from 1 x 10(-6) to 1.2 x10(-4)M with a detection limit of 5 x 10(-7)M. The SA-BMP was able to detect the amplicons of 1pg DNA template of B. Cereus bacteria, thus providing better detection sensitivity than conventional gel-based electropherograms.
authors.affiliation: Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, PA 19104-6315, USA.
authors.forename: Changchun
authors.initials: C
authors.lastname: Liu
authors.forename: Michael G
authors.initials: MG
authors.lastname: Schrlau
authors.forename: Haim H
authors.initials: HH
authors.lastname: Bau
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D004563:Electrochemistry / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008863:Microspheres