High-brightness near-infrared fluorescent composite microsphere and preparation method thereof

The invention discloses a high-brightness near-infrared fluorescent composite microsphere and a preparation method thereof, and the preparation method comprises the following steps: doping Cypate dye into silicon dioxide nanoparticles by using a method to obtain dye silicon dioxide microsphere Cypate coated SiO2 microspheres; the preparation method comprises the following steps: carrying out amination on the surface of a microsphere, carrying out layer-by-layer self-assembly of quantum dots on the surface of the aminated dye microsphere by using PAH, carrying out carboxylation on the surface of the assembled microsphere by using polyacrylic acid (PAA), and adding glutaraldehyde to increase chemical connection of two adjacent PAH layers so as to obtain the high-brightness near-infrared fluorescent composite microsphere. 本发明公开了一种高亮度的近红外荧光复合微球及其制备方法，利用法将Cypate染料掺杂进入二氧化硅纳米颗粒，得到染料二氧化硅微球Cypate@SiO2微球；对微球表面氨基化后在氨基化染料微球表面利用PAH逐层自组装量子点，组装后的微球采用聚丙烯酸(PAA)对微球表面进行羧基化，再加入戊二醛对两层邻近的PAH层增加化学连接，得到高亮度的近红外荧光复合微球。