Bio-macromolecular detection: new organic vital dyes

Aggregates of lipids or proteins are associated with high incidence diseases. The detection of these bio-macromolecules is a key issue in both fundamental research studies and in medical diagnostics. Push-pull chromophores and luminogenic materials with aggregation-induced emission (AIE) properties have gained importance as dyes in biological studies and diagnostics.

Here, we will describe our recent work on the synthesis and characterization of a group of fluorescent probes with affinity for lipid or protein aggregates. Optoelectronic properties and biological evaluation of the fluorophores will also be presented. As lipid aggregates are concerned, one of the tested dyes showed good fluorescence intensity in cells, lipid vesicles, zebrafish embryos and presented altered emission spectra depending on the polarity of the medium, due to its push-pull character. This fluorophore demonstrated to be suitable for high-content screens for the diagnosis of Farber’s disease, a lysosomal storage disease. Furthermore, a new protein aggregate AIEgen was used as a biological vital dye and proved to be a promising fluorescent probe for the selective staining of protein aggregates, allowing imaging by fluorescence confocal microscopy, with a selectivity comparable to a commercial dye, and for detection of protein aggregates in routine diagnosis.