The design and development of Janus suprabeads (JSs) with multiple responses are highly desirable in the fabrication of functional nanomaterials. In this work, we report a triphase microfluidic strategy for the construction of JSs with temperature-magnetism-optics triple responses. Initially, macromonomer poly(methacrylic acid) (PMAA) obtained via catalytic chain transfer polymerization (CCTP) was grafted onto the polystyrene (PS) colloidal photonic crystals (CPCs) surface. Because abundant carboxylic acid groups in PMAA could coordinate cadmium ions for in situ production of fluorescent CdS quantum dots (QDs) after introducing sulfur ions, the as-prepared JSs were endowed with favorable optical properties. Meanwhile, the as-prepared Cd(2+)/PS CPCs were employed as a template to build JSs with temperature-magnetism sensitivity via the introduction of magnetic Fe3O4 and hydrogels. Finally, the fluorescence pattern was easily performed by using chalcogenides as "ink" to write on the pad, in which in situ reaction mechanism was involved in the response. The multiple responsive JSs show promising applications in sensor, display, and anticounterfeit fields.
Keywords: Janus suprabeads; colloidal photonic crystals; display; microfluidics; sensor.