Drug screening strategies using metal-based luminescent probes

Drug screening assays employing organic fluorophores are widely used for high-throughput screening of potential drugs. However, organic dyes generally possess short lifetimes and narrow Stokes shifts, and are susceptible to background signal interference. In recent years, metal-based luminescent probes, such as transition metal complexes (e.g. Ir(III), Ru(II)), lanthanide complexes (e.g. Eu(III) and Tb(III)), and metal-based nanomaterials or quantum dots, have found increasing use for biosensing and bioimaging owing to their distinct spectral and structural characteristics. In this review, we first introduce the photophysical properties of metal-based luminescent probes, and then describe representative examples of metal-based luminescent probes and their applications for drug screening, including competitive, oligonucleotide-based, reaction-based, and assembly-based drug screening strategies. We also present the combination of these metal-based probes with luminescence microscopy (e.g. TRES) or imaging techniques (e.g. PLIM), which could open new doors for translational biomedical and/or (pre)clinical studies of biomolecular regulators in more challenging biological systems.