A novel cell-impermeable fluorescent zinc sensor containing poly(ethylene glycol) chain

A novel cell-impermeable zinc sensor was synthesized by incorporating poly(ethylene glycol) (PEG) to N-(8-quinolyl)-p-aminobenzenesulfonamide (HQAS) group. The polymeric zinc sensor combines both valuable features of HQAS and PEG. The HQAS of the sensor has the similar functions to TSQ, and exhibits a good fluorescence response to Zn2+ but poor fluorescence responses to other metal ions. The PEG chain can prevent the sensor to permeate healthy cell membrane. The stained experiments with the yeast cells as model showed that the sensor cannot stain the healthy yeast cells, but only the damaged or died yeast cells. These results indicated the novel zinc probe was a typical cell-impermeable zinc sensor.