Construction of GSH activated near-infrared fluorescent and photoacoustic dual-modal probe for in vivo tumor imaging

The probe plays a pivotal role in the early diagnosis of tumor, especially tumor microenvironment (TME)-responsive probe, which could exploit differences between tumor and normal tissue to achieve better signal-to-noise ratio. In view of overexpressed glutathione (GSH) in microenvironment considered as one of the important characteristics of tumor distinct from normal tissue, we constructed a GSH activated near-infrared fluorescent (NIRF) and photoacoustic (PA) dual-modal probe (Probe-GSH) based on the hybrid of xanthene-based hemicyanines and dicyanoisophorone. The activated Probe-GSH could exhibit 8-fold PA signal/10-fold NIRF intensity enhancement. Besides, compared with the existing xanthene-based hemicyanines (XBH), Probe-GSH possessed longer absorbance/emission wavelength and larger Stokes shift. More importantly, Probe-GSH has been successfully applied to the image of 4T1-bearing tumor mice under NIRF and PA dual modality.