Magnetically-Refreshable Receptor Platform Structures for Reusable Nano-biosensor Chips*

We developed a magnetically-refreshable receptor platform structure which can be integrated with quite versatile nano-biosensor structures to build reusable nano-biosensor chips. This structure allowed us to remove used receptor molecules easily from a biosensor surface and to reuse the biosensor for repeated sensing operations. Using this structure, we demonstrated reusable immunofluorescence biosensors. Significantly, since our method can be used to place receptor molecules very close to a nano-biosensor surface, it can be utilized to build reusable carbon nanotube transistor-based biosensors which require receptor molecules within a Debye length from the sensor surface. Furthermore, we also show that a single sensor chip can be utilized to detect two different target molecules simply by replacing receptor molecules using our method. Since this method does not rely on any chemical reaction to refresh sensor chips, it can be utilized for versatile biosensor structures and virtually-general receptor molecular species.