2687198-42-9

Biological Activity: TPE-SQ5 is a ratiometric Fluorescent probe for hypochlorite (ClO^-) detection with a limit of detection of 5.6 nM. TPE-SQ5 exhibits high selectivity and high sensitivity towards ClO^-. TPE-SQ5 can be oxidized by ClO^- to form an epoxide, which quenches its deep red fluorescence; subsequently, the epoxide decomposes into a hemicyanine and a sulfonic acid-substituted oxindole, producing blue-green fluorescence to achieve a ratiometric response. TPE-SQ5 can form nanoparticles with Pluronic F-127 via the nanoprecipitation method, and these nanoparticles possess cell permeability. TPE-SQ5 has unique Ex/Em spectra in different solvents and nanoparticle forms, with emission peaks at 643 nm (380 nm excitation, 95% H₂O/THF), 631 nm (564 nm excitation, DMSO), 652 nm (536 nm excitation, THF) and 630 nm (524 nm excitation, nanoparticles); the Ex/Em settings used for cell imaging are 488/550-650 nm (red channel) and 405/450-550 nm (green channel)^[1][2].