Monitoring interfacial lectin binding with nanomolar sensitivity using a plasmon field effect transistor.

By immobilizing glycopolymers onto the surface of the recently developed plasmonic field effect transistor (FET), the recognition between lectins and surface-immobilized glycopolymers can be detected over a wide dynamic range (10-10 to 10-4 M) in an environment that resembles the glycocalyx. The binding to the sensor surface by various lectins was tested, and the selectivities and relative binding affinity trends observed in solution were maintained on the sensor surface, and the significantly higher avidities are attributed to cluster-glycoside effects that occur on the surface. The combination of polymer surface chemistry and optoelectronic output in this device architecture produces amongst the highest reported detection sensitivity for ConA. This work demonstrates the benefits that arise from combining emerging device architectures and soft-matter systems to create cutting edge nanotechnologies that lend themselves to fundamental biological studies and integration into point-of-use diagnostics and sensors.

Plasmon Field Effect Transistor for Plasmon to Electric Conversion and Amplification.

Direct coupling of electronic excitations of optical energy via plasmon resonances opens the door to improving gain and selectivity in various optoelectronic applications. We report a new device structure and working mechanisms for plasmon resonance energy detection and electric conversion based on a thin film transistor device with a metal nanostructure incorporated in it. This plasmon field effect transistor collects the plasmonically induced hot electrons from the physically isolated metal nanostructures. These hot electrons contribute to the amplification of the drain current. The internal electric field and quantum tunneling effect at the metal-semiconductor junction enable highly efficient hot electron collection and amplification. Combined with the versatility of plasmonic nanostructures in wavelength tunability, this device architecture offers an ultrawide spectral range that can be used in various applications.