Surface Plasmon Coupled Fluorescence-Enhanced Interfacial “Molecular Beacon” To Probe Biorecognition Switching: An Efficient, Versatile, and Facile Signaling Biochip

Abstract

Integrating probes and a substrate together, a fluorescence-enhanced interfacial "molecular beacon" (FEIMB) is demonstrated, based on directional surface plasmon coupled emission. Through this simple yet efficient interfacial modulation engineering to create an interfacial quencher (graphene oxide)-enhancer (gold nanofilm) pair, the quenching-to-enhancing region of FEIMB can be actively tuned. Therefore, it provides a spatial match between signal transduction and interface-mediated biorecognition switching. Via combination of strong quenching and efficient plasmonic coupling, a synergistically amplified signal-to-background ratio of >1000-fold has been achieved. FEIMBs have been employed in protein and DNA detection, creating a high-performance and universal chip-based plasmon-mediated fluorescence sensing platform.