Cavity Quantum Electrodynamics on a Single Gold Nanoprobe for Biological Application

Cavity quantum electrodynamics (CQED) is an interesting phenomena but difficult to realize. Here, we report the probe that allows strong coupling with biological molecules within a single particle. We accomplish CQED structure in a single gold double nanoring with an intrinsic nanogap of 4-8 nm. We observe topological CQED characteristics in dark-field microscopy measurements.<br/>This CQED probe can be applied to the living cells, showing extraordinary ability to amplify biomolecular signal through strong coupling between the CQED probe and biomolecules. We believe that this 3D CQED nanocavity is a promising nanoprobe for detection of small molecules in the cells and a platform for breakthrough biomolecular studies.