Versatile Bifunctional Magnetic-Fluorescent Responsive Janus Supraballs Towards the Flexible Bead Display

The first microfluidic synthesis of ionomer-based bifunctional Janus supraballs possessing two distinct magnetic-nanoparticle-dropped and quantum dot polymer hemispheres within an anisotropic structure is reported. Based on such Janus supraballs with stable fluorescence and superparamagnetism, a magneto-responsive fluorescent switch is developed to realize free-writing under a magnetic field. This is a promising, simple way to fabricate novel flexible bead displays.