Triphenylamine Schiff base as a lipid droplet-targeted fluorescent probe using Si–O–Si as a bridge for the detection of Cr6+ applied in bio-imaging

Abstract

Lipid droplets are known to play an important role in many cellular activities, as revealed by recent studies. Additionally, hexavalent chromium is considered extremely toxic because it readily passes through cellular membranes and easily accumulates in living cells. In this study, a novel lipid droplet-targeted fluorescent probe (Si-LDS) for recognition of Cr⁶⁺ in living cells was designed and synthesized using triphenylamine derivatives and organosiloxane. Si-LDS detected Cr⁶⁺ with high selectivity and sensitivity. The novel probe was successfully applied to cell imaging of exogenous Cr⁶⁺ in HeLa cells, and Si-LDS was able to localize mainly in the lipid droplets of HeLa cells. Si-LDS is the first lipid droplet-targeted fluorescent probe for monitoring Cr⁶⁺.