Reusable Biosensing Platforms Based on Magnetically-refreshable Receptor Structures

We report a magnetically-refreshable receptor platform (MRP) structure which can be integrated with versatile nanodevice-based sensors to build reusable biosensors using virtually-general receptor molecules. This structure allows one to trap or detrap receptors on nano-biosensor surfaces for repeated sensing operations. As a proof of concepts, we demonstrated the repeated sensing measurements of fluorescence biosensors and field-effect transistor (FET)-based biosensors. Significantly, our method enables the assembly of single-layered structures of receptor-functionalized nanobeads on the transducer surface, so that an active antibody can be placed within a Debye length from the sensor surface. Furthermore, we also showed that a single sensor chip could be utilized to detect two different target molecules simply by replacing receptor molecules. Since our method enables multiple biosensing operations by applying external magnetic fields without any harsh chemical treatment, it can be utilized for virtually-general receptor molecular species and versatile biosensor structures.