Clickable multifunctional dumbbell particles for in situ single-cell cytokine detection

We report a novel strategy for fabrication of multifunctional dumbbell particles (DPs) through click chemistry for monitoring single-cell cytokine releasing. Large scale of two different size DPs were prepared through a covalent bioorthogonal reaction between methyltetrazine and trans-cyclooctene on a microchip under a magnetic field. After DP collection from the microchip, the two sides of each particle were further functionalized with different antibodies for cell capturing and cytokine detection, respectively. Upon modification with different dyes, these DPs could be used for multiplex detection and analysis of cytokines secreted by live cells. These results clearly show that the DPs are promising for use in cell sorting, bioimaging, single-cell analysis and biomedical diagnostics.