Figure 1.

Glycocalyx engineering strategy to visualize plasma membrane proton fluxes: (A) Cells expressing ion channels or membrane transporters are incubated with an azidosugar (azido group in blue) and the cell surface is subsequently labeled with a fluorescent pH sensor (pH-DIBO) to detect proton fluxes. The azide-reactive and fluorescent pH-sensitive groups in the chemical structure and label are colored blue and red, respectively. (B) Scheme for the synthesis of pH-DIBO.