Carbon Dots-Plasmonics Coupling Enables Energy Transfer and Provides Unique Chemical Signatures

Plasmonic nanostructures and carbon dots (C-dots) are fascinating optical materials, utilized in imaging, sensing, and color generation. Interaction between plasmonic materials and C-dots may lead to new hybrid materials with controllable optical properties. Herein, we demonstrate for the first time coupling between plasmonic modes and C-dots deposited upon a plasmonic silver hole array. The coupling leads to a remarkable visual attenuation and shifts of the plasmonic wavelengths (i.e., color tuning). In particular, the C-dots plasmon couplings and pertinent color transformations depend both upon the C-dots' fluorescence emission wavelengths and functional residues displayed upon the C-dots' surface. This optical modulation corresponds to energy level alignment and consequent energy transfer between the C-dots and the plasmonic silver hole array. Notably, the energy coupling observed in the C-dot plasmonic hybrid system allows distinguishing between C-dots species exhibiting similar optical properties, albeit displaying different functional residues.