Lanthanide Nanoparticules as Photoluminescent Reporters

Abstract

Luminescent lanthanide nanoparticles provide a combination of high luminescence intensity, long luminescence lifetime, sharp emission peaks with narrow bandwidth, and a large Stokes’ shift, leading to a high-performance reporter technology for bioanalytical assays. The high specific activity of luminescent lanthanide nanoparticles enables improved assay sensitivities compared to the conventional fluorescent reporters, and the different luminescent lanthanide ions with well-separated emission wavelengths facilitate multiparametric assays. The versatility of lanthanide chelate-doped polymeric nanoparticles as reporters is further increased by the use of the most effective organic light-harvesting ligands optimized for enhanced luminescence and the availability of inexpensive highpower solid-state light sources. Moreover, entrapping within polymeric nanoparticles allows the use of the lanthanide complexes with a weak water solubility or a low thermodynamic stability. In this review, we discuss the effects of nanoparticle composition, particle size, synthesis, surface modification, and biomolecule conjugation on the assay performance in addition to applications of these reporters in both heterogeneous and homogeneous assays. In the future, additional value may be provided by hybrid lanthanide nanoparticles, which combine, e.g., luminescent and magnetic properties for detection and controlling the assay kinetics and washing efficiency.