Despite the rapid development of fluorescence detection modalities for disease diagnosis,novel fluores-cent molecules and probes still face with tremendous pressure to transform before employing such flu-orescent tools in the clinic.Impressively,the fluorescent probes based on the traditional fluorescent dye are expected to accelerate the transformation process.Herein,methylene blue is requisitioned to design the GSH responsive probe MB-SS-CPT elaborately.The as-synthesized MB-SS-CPT provides a dramatic optical advantage for GSH detection in vitro,cell fluorescence imaging,in vivo imaging,and antitumor therapy.