A stimuli-responsive and chemically tunable organic microcrystal laser switch.

We demonstrated a stimuli-responsive and chemically switchable organic microbelt laser through reversible protonation-deprotonation reactions. The parent microbelt cavity together with the optically allowed 0-1 transition of H-aggregates enables a microlaser to operate at 585 nm. Upon HCl vapor treatment, the protonation of surface molecules shifts the lasing wavelength to 560 nm, generating an intensity contrast ratio >105, accompanied by a sharp color change from orange (deprotonated) to green (protonated).

A sensitive probe for amyloid fibril detection with strong fluorescence and early response.

We synthesized a new probe, 4-[2-(2-naphthyl)-()-ethenyl]-benzyl(triphenyl)phosphonium bromide (NEB), to detect the formation of amyloid fibrils of bovine insulin. The fluorescence intensity of NEB in the presence of insulin fibrils was 30 times higher than that before fibrillation, with the fluorescence quantum yield increased from 2.5% to 78%.