A novel and simple one-step synthetic method for monocarboxylate near-infrared cyanine dyes was developed. A hydrophilic zwitterionic probe was presented for imaging of apoptotic cells driven by its inherent chemical structure. The probe with antitumor drug gemcitabine was conjugated for effective apoptosis imaging. Real-time monitoring and image-guided therapy for gastric tumors were displayed by the apoptosis specific dye-drug conjugate.