Efficient collection and sensitive detection using conducting magnetic microbeads.

Conducting magnetic microbeads were successfully fabricated through a simple procedure that involves coating magnetic microbeads with gold nanoparticles. The formation of a gold layer on the bead enabled the simple introduction of a biotin probe onto the bead, resulting in the binding capacity with streptavidin being 10 times greater than that of commercially available biotin-binding magnetic beads. In addition to the high recovery via magnetic forces and high dispersibility in the sample solution, the accumulation of highly conductive beads on the electrode resulted in the amplification of the electrochemical response of the detection system. This paper reports the efficient collection and highly sensitive detection of target biomolecules using Au-coated magnetic microbeads.