Polynuclear transition metal complexes: emerging agents for bacterial imaging and antimicrobial therapy

Polynuclear transition metal complexes (PTMCs) represent a promising class of compounds with significant potential for advancing microbial diagnostics and treatment due to their multifunctional properties. This perspective highlights recent progress in the design of PTMCs for detecting and combating microbial infections. Complexes with multiple metal centers, such as silver(I), rhenium(I), iron(II), cobalt(II), nickel(II), copper(II), zinc(II), cadmium(II), ruthenium(II), iridium(III), gold(I), and gold(III), exhibit a wide range of structural motifs and are effective against a broad spectrum of multidrug-resistant bacterial infections. PTMCs show their antimicrobial effects through several mechanisms that include the generation of reactive oxygen species, which cause oxidative stress and damage bacterial cells, disrupt bacterial membranes, bind selectively to bacterial biomolecules, and interfere with critical cellular functions. Additionally, luminescent PTMCs are ideal for real-time imaging and tracking of bacterial cells during infection. In this perspective, we discuss their various applications, safety concerns, and emerging trends in the clinical use of PTMCs due to their enormous possibilities for future medical applications.