Ruthenium pyrene complexes: synthesis, characterization and interaction with bovine serum albumin

Bovine serum albumin (BSA) is often used as a model protein for human serum albumin, which plays an important role in metabolism.[1] Fluorescence spectroscopy is an attractive method for sensing applications as it is fast, practical, highly sensitive and selective. Ruthenium complexes with organic ligands are widely studied as potential anticancer drugs with some compounds reaching phase II of clinical trials.[2] Continuing our previous work on ruthenium phosphine complexes with anticancer activity, [3] in this paper we describe two ruthenium complexes 1 and 2, both substituted with pyrene – a fluorescent group. Intriguingly, 1 and 2 pyrene emission is completely quenched in water, and mostly reconstituted upon binding to BSA, thus 1 and 2 behaving as switch-on sensors. In addition, the cytotoxicity of the complexes with and without irradiation will be discussed, suggesting their potential use as PTD drugs.