A highly sensitive probe detecting low pH area of HeLa cells based on rhodamine B modified beta-cyclodextrins.

Two kinds of rhodamine modified beta-cyclodextrins (R-1 and R-2), which are coupled up ethylene diamine (EDA) and tetraethylene pentamine (TEPA) between Rh B and beta-cyclodextrin, respectively, have been synthesized. R-1 and 2 work as a new fluorogenic probe for monitoring pH of Hela cells, and MTT of assay R-1, R-2, and rhodamine B indicate that less a cytotoxicity of those R-1 and R-2 than that of rhodamine B, where R-1 has much less one than that of R-2. The fluorogenetic probe capability of R-2 was recognized in an area of acidic area in living cell, which is lysosome.