PROBLEM TO BE SOLVED: To provide a marker for a biosensor, a biosensor, and a marker detection method for the biosensor, capable of inexpensive and highly-sensitive detection without using an expensive sensor having ultra-high sensitivity or the like. SOLUTION: The marker used for the biosensor comprises magnetic particle species 5 immobilized near a detection position of the biosensor together with a target biomaterial 4, and a plurality of magnetic particles 20 adsorbed in a pillar shape onto the magnetic particle species 10 to form a magnetic particle pillar 30 by application of an external magnetic field H. The magnetic particle pillar 30 is formed by application of an external magnetic field H, and the marker comprising the magnetic particle species 10 and the magnetic particle pillar 30 is detected by the biosensor. COPYRIGHT: (C)2008,JPO&INPIT
