A naphthalimide-based fluorescent probe with mitochondria targeting for GSH sensing and cancer cell recognition

GSH is an important biological thiol which involves many biological processes, and also an biomarker for cancer. So it's urgent to develop fluorescent probes with excellent sensitivity and high selectivity for GSH detection. Herein, we develop a new GSH-responsive fluorescent probe TPP-Naph-SS-Fc based on PET (photoinduced electron transfer) mechanism. TPP-Naph-SS-Fc contains naphthalimide fluorephore, the ferrocene quencher, the disulfide cleavage bond and the triphenylphosphine mitochondrial localizer. It shows a fluorescence turn-on response toward GSH for cleavage the disulfide bond, which result in the blocking of PET process. Especially, this probe can localize in mitochondria and make real-time imaging of GSH, also demonstrate the ability to distinguish between cancerous and normal cells.