先用硫脲修饰的量子点为核， 再用聚丙烯酸包覆， 并用聚乙烯吡咯烷酮K-30为稳定剂， 合成粒径分布均匀、 性能稳定的核壳结构水溶性量子点荧光体。 采用荧光发射光谱、 红外光谱和透射电镜对样品进行表征并探索核量子点在聚丙烯酸聚合物溶液中含量对量子点荧光体的影响。 结果表明: 聚丙烯酸修饰后量子点粒径分布更均匀; 荧光发射主峰由548 nm蓝移到448 nm。 红外光谱图中2 092.8和1 384.3 cm-1分别归属于羧基的CO和C—O伸缩振动， 1 644.5 cm-1归属为酰胺键的CO伸缩振动， 核量子点在聚丙烯酸聚合物溶液中最佳含量为2.67 mg·mL-1。 该量子点制备方法简单易行， 具有较好的稳定性及高荧光量子效率， 为进一步应用于生物标记奠定基础。

Cd-Zn quantum dots (QDs) modified with thiourea was firstly prepared asthe cores, then the cores were coated with polyacrylic acid with PVP K-30 as the stabilizer in water-soluble reaction system. The water-soluble fluorescence QDs were the same size and stable. The water-soluble QDs were characterized by fluorescence emission spectra, infrared spectra (IR), and transmission electron microscopy（TEM）. The effects of the nuclear QDs with different concentration under polyacrylic acid solution on the optical properties of QDs were also studied. The results showed that the nanoparticles of QDs modified with polyacrylic acid have more uniform particle distribution, and the main peak was blueshifted from 548 to 448 nm. CO and C—O stretching vibration absorption peaks were 2 092.8 and 1 384.3 cm-1 in infrared spectra, amide bond of CO stretching vibration absorption peaks were 1 644.5 cm-1. The best concentration of nuclear QDs under polyacrylic acid solution was 2.67 mg·mL-1. QDs prepared by this simple method have good stability and strong fluorescence intensity. The approach introduced in this paper will lay a solid foundation for biological markers and applications of QDs in the future.