Provided herein is a new generation of PDT agents based on porphyrin-lanthanide complexes with specific functional groups which can specifically localize on particular tumors, and their PDT processes can be monitored via NIR emission from erbium. In particular, provided herein is a multi-modal lanthanide-porphyrin PDT agent (Er-R3) that are capable of killing the bladder tumor cells selectivity via1O2 from porphyrin moiety and affording the fluorescence imaging simultaneously upon Er-R3 binding with the integrin αvβ3 isoform in bladder cancer cells.
