Development of a red-emissive two-photon fluorescent probe for sensitive detection of beta-galactosidase in vitro and in vivo

beta-galactosidase plays an important role in early cancer diagnosis and is widely used in examine transcription and transfection efficiencies. In addition, abnormally accumulated beta-galactosidase activity has been widely accepted marker of cellular senescence. Therefore, it is necessary to develop an effective method to detect beta-galactosidase activity in biological systems. To achieve this goal, we have developed a fluorescent probe-by using Rho as a fluorophore and linking it to galactose via an ether bond for sensing beta-galactosidase. The probe TR-G with high selectivity and sensitivity has an emission wavelength above 600 nm, and further, cell and two-photon tissue imaging are performed and an excellent tissue penetration is presented. Thus, TR-G is able to detect beta-galactosidase in vivo and in vitro.