Theoretical study on the lasing plasmon of a split ring for label-free detection of single molecules and single nanoparticles

Abstract

This paper reports the plasmonic lasing of a split ring filled with gain material in water. The lasing mode (1500 nm) is far from the pump mode (980 nm), which can depress the detection noise from the pump light. The laser intensities of the two modes simultaneously increase by more than 10 3 in amplitude, which can intensify the absorption efficiency of the pumping light and enhance the plasmonic lasing. The plasmonic lasing is a sensitive sensor. When a single protein nanoparticle (n = 1.5, r = 1.25 nm) is trapped in the gap of the split ring, the lasing spectrum moves by 0.031 nm, which is much larger than the detection limit of 10 −5 nm. Moreover, the lasing intensity is also very sensitive to the trapped nanoparticle. It reduces to less than 1/600 when a protein nanoparticle (n = 1.5, r = 1.25 nm) is trapped in the gap.

A primary model of decoherence in neuronal microtubules based on the interaction Hamiltonian between microtubules and plasmon in neurons

“…However, the electromagnetic interaction is essential in the scale of molecules, so this model could be used for reference when dealing with the interaction between the ions in 048701-6 cell environment and dipoles of bio-molecules. A direct experiment to verify this model is hard to be carried out at this time but with the development of ultrafast biophysics, quantum information, quantum optics, and imaging technology, [37][38][39][40][41] the experiment could be carried out in the future.…”