Research related to the development and application of luminescent nanoparticles (LNPs) for chemical and biological analysis and imaging is flourishing. Novel materials and new applications continue to be reported after two decades of research. This review provides a comprehensive and heuristic overview of this field. It is targeted to both newcomers and experts who are interested in a critical assessment of LNP materials, their properties, strengths and weaknesses, and prospective applications. Numerous LNP materials are cataloged by fundamental descriptions of their chemical identities and physical morphology, quantitative photoluminescence (PL) properties, PL mechanisms, and surface chemistry. These materials include various semiconductor quantum dots, carbon nanotubes, graphene derivatives, carbon dots, nanodiamonds, luminescent metal nanoclusters, lanthanidedoped upconversion nanoparticles and downshifting nanoparticles, triplet−triplet annihilation nanoparticles, persistent-luminescence nanoparticles, conjugated polymer nanoparticles and semiconducting polymer dots, multi-nanoparticle assemblies, and doped and labeled nanoparticles, including but not limited to those based on polymers and silica. As an exercise in the critical assessment of LNP properties, these materials are ranked by several application-related functional criteria. Additional sections highlight recent examples of advances in chemical and biological analysis, point-of-care diagnostics, and cellular, tissue, and in vivo imaging and theranostics. These examples are drawn from the recent literature and organized by both LNP material and the particular properties that are leveraged to an advantage. Finally, a perspective on what comes next for the field is offered.

During cell division, chromosomes attach to spindle microtubules at sites called kinetochores, and force generated at the kinetochore-microtubule interface is the main driver of chromosome movement. Surprisingly, kinetochores are not required for chromosome segregation on acentrosomal spindles in Caenorhabditis elegans oocytes, but the mechanism driving chromosomes apart in their absence is not understood. In this study, we show that lateral microtubule–chromosome associations established during prometaphase remain intact during anaphase to facilitate separation, defining a novel form of kinetochore-independent segregation. Chromosome dynamics during congression and segregation are controlled by opposing forces; plus-end directed forces are mediated by a protein complex that forms a ring around the chromosome center and dynein on chromosome arms provides a minus-end force. At anaphase onset, ring removal shifts the balance between these forces, triggering poleward movement along lateral microtubule bundles. This represents an elegant strategy for controlling chromosomal movements during cell division distinct from the canonical kinetochore-driven mechanism.DOI: http://dx.doi.org/10.7554/eLife.06462.001

Female reproductive cells of most species lack centrosomes, but how spindles form in their absence is poorly understood. Study of oocytes in Caenorhabditis elegans uncovers new steps in this process and reveals mechanisms required for acentrosomal spindle bipolarity via studies of two proteins, KLP-18/kinesin-12 and MESP-1.

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Near‐infrared‐emitting polymers were prepared using four boron‐difluoride‐curcuminoid‐based monomers using ring‐opening metathesis polymerization (ROMP). Well‐defined polymers with molecular weights of ≈20 kDa and dispersities <1.07 were produced and exhibited near‐infrared (NIR) emission in solution and in the solid state with photoluminescence quantum yields (ΦPL) as high as 0.72 and 0.18, respectively. Time‐resolved emission spectroscopy revealed thermally activated delayed fluorescence (TADF) in polymers containing highly planar dopants, whereas room‐temperature phosphorescence dominated with twisted species. Density functional theory demonstrated that rotation about the donor–acceptor linker can give rise to TADF, even where none would be expected based on calculations using ground‐state geometries. Incorporation of TADF‐active materials into water‐soluble polymer dots (Pdots) gave NIR‐emissive nanoparticles, and conjugation of these Pdots with antibodies enabled immunofluorescent labeling of SK‐BR3 human breast‐cancer cells.