Acid-triggered release of doxorubicin from a hydrazone-linked Gd3+-texaphyrin conjugate

The hydrazone-based Gd³⁺-texaphyrin doxorubicin conjugate 1, releases active doxorubicin at acidic pH values, allowing its components to be followed by two complementary imaging methods, namely Off–On fluorescence enhancement and MR imaging.