Circularly polarized luminescence bioimaging using chiral BODIPYs: A model scaffold for advancing unprecedented CPL microscopy using small full-organic probes

Abstract

Unprecedented circularly polarized luminescence bioimaging (CPL-bioimaging) of live cells using small full-organic probes is first reported. These highly biocompatible and adaptable probes are pivotal to advance emerging CPL Laser-Scanning Confocal Microscopy (CPL-LSCM) as an undeniable tool to distinguish, monitor, and understand the role of chirality in the biological processes. The development of these probes was challenging due to the poor dichroic character associated with the involved CPL emissions. However, the known capability of the BODIPY dyes to be tuned to act as efficient fluorescence bioprobes, together with the capability of the BINOL-O-BODIPY scaffold to enable CPL, allowed the successful design of the first examples of this kind of CPL probes. Interestingly, the developed CPL probes were also multiphoton (MP) active, paving the way for the envisioned MP-CPL-bioimaging. The described full-organic CPL-probe scaffold, based on an optically and biologically tunable BODIPY core, which is chirally perturbed by an enantiopure BINOL moiety, represents, therefore, a simple and readily accessible structural design for advancing efficient CPL probes for bioimaging by CPL-LSCM.