On-demand one-step synthesis of small-sized fluorescent-magnetic bifunctional microparticles on a droplet-splitting chip.

A facile and controllable method for one-step synthesis of small-sized monodisperse fluorescent-magnetic bifunctional microparticles based on droplet splitting and photopolymerization was established. Using this method, magnetic nanoparticles and acryloyl rhodamine B (acryloyl-RhB) molecules were incorporated into the dispersed phase, which allowed the direct generation of functional microparticles. Functional microparticles with diameters in the range of 2.8 to 19.2 μm were obtained by controlling the fluidic characteristics. The fluorescence intensity of the microparticles could be regulated by adjusting the concentration of the acryloyl-RhB molecule in the dispersed phase. Furthermore, the fluorescent-magnetic bifunctional microparticles were successfully used to detect proteins specifically by ratiometric fluorescence analysis, showing their potential in biological sample detection.