We study the strong coupling between the molecular excited state and the plasmonic modes of silver hole arrays with a resonant frequency very close to the asymptotic line of the plasmonic dispersion relation, at the nonlinear regime. We demonstrate that the strong coupling regime can be achieved between the two subsystems at low molecular densities with negligible damping of the electromagnetic field.Our results are supported by rigorous numerical simulations showing that the strong coupling is observed when the molecular transition lies within the nonlinear regime of the dispersion relation rather than the linear regime.

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.

Bacterial conjugation is a highly ubiquitous and promiscuous process, by which a donor bacterium transfers a large portion of genetic material to a recipient cell. This mechanism of horizontal gene transfer plays an important role in bacterial evolution and in the ability of bacteria to acquire resistance to antimicrobial drugs and disinfectants.

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