Design a novel multifunctional (CsPbBr3/Fe3O4)@MPSs@SiO2 magneto-optical microspheres for capturing circulating tumor cells

Abstract All inorganic lead halide perovskite nanocrystals with excellent photoelectric characteristics as one of attractive new photoelectric materials are capable to apply in a variety of optoelectronic devices, but their instability and toxicity strongly impedes biological application. Herein, a novel approach of combining physical loading with hydrolytic packaging was exploited to firstly implant CsPbBr3 nanocrystals (NCs) and Fe3O4 quantum dots (QDs) into the mesoporous polystyrene microspheres (MPSs), then a silica shell layer was further coated on it to form the stable, safe and non-toxic (CsPbBr3/Fe3O4)@MPSs@SiO2 magneto-optical microspheres. The double core-shells packaging way not only improves the stability of the magneto-optical microspheres, but also avoids direct contact between CsPbBr3 NCs and biological target such as circulating tumor cells (CTCs) to solve the problem of heavy metal Pb in such material system. These magneto-optical microspheres can capture CTCs from both breast cancer cells (MCF-7) and lung cancer patient's blood in a few minutes. This work created a simple, safe and one-step method to identify and capture CTCs, which opens a new chapter for the application of lead halide perovskite in the biological field.