Chiral polymer dots for ratiometric enantioselective monitoring of D-cysteine in the brains of Alzheimer's disease mice.

It is imperative to develop reliable in vivo chiral discrimination methods to detect enantiomer D-cysteine (D-Cys) involved in brain chemistry to further understand its functions in pathological and physiological events in brains. We herein fabricated an integrated polymer dot (Pdot)-based nanoprobe, BFD@Ch-pdots, derived from a newly designed chiral polymer and Cys-responsive dye for ratiometric imaging of D-Cys in cells and brains. The Pdots exhibited high enantioselectivity, good biocompatibility, and efficient blood-brain barrier (BBB) penetration. The results demonstrate that the D-Cys level is substantially elevated in AD mice brains.