NIR absorbing DICPO derivatives applied to wide range of pH and detection of glutathione in tumor

New DPCO derivatives were developed for application at a wide range of pH values. Cl-DPCO exhibited better optical properties than DPCO in solutions with pH values from 5.0 to 9.0 and was preferable for the design of probes, especially for the imaging of a tumor micro-environment which is acidic. With Cl-DPCO probe 1 was designed for the detection of GSH. Probe 1 was sensitive to GSH in environments at pH values of 5.7 and 7.4, and strong near-infrared fluorescence was detected. Moreover, probe 1 had good response to the endogenous GSH in living cells, which suggested that Cl-DPCO has potential in the design of other tumor-associated probes.