Observations of the effect of confined space on fluorescence and diffusion properties of molecules in single conical nanopore channels.

In this work, we investigated the fluorescence emission spectra and diffusion properties of dye molecules confined in different positions of conical nanopore channels using a laser scanning confocal fluorescence microscope. The results showed that a red shift of the emission spectra is observed from the tip section to the bottom section and the diffusion rate is slower in the channel than that in bulk solution, indicating a single conical nanopore channel can be used as a convenient tool for investigating the effect of confined space on the behaviors of molecules.