Characterization and separation of semiconductor quantum dots and their conjugates by capillary electrophoresis

Semiconductor quantum dots (QDs) are very important luminescent nanomaterials with a wide range of potential applications. Currently, QDs as labeling probes are broadly used in bioassays, including immunoassay, DNA hybridization, and bioimaging, due to their excellent physical and chemical properties, such as broad excitation spectra, narrow and size-dependent emission profiles, long fluorescence life time, and good photostability. The characterization of QDs and their conjugates is crucial for their wide bioapplications. CE has become a powerful tool for the separation and characterization of QDs and their conjugates. In this review, some CE separation models of QDs are first introduced, mainly including CZE, CGE, MEKC, and ITP. And then, some key applications, such as the measurements of size, surface charge, and concentration of QDs and the characterization of QDs conjugates (e.g. QD-protein, QD-DNA, QD-small molecule), are also described. Finally, future perspectives are discussed.