巯基丙酸、巯基水杨酸双修饰CdSe量子点的合成及其标记水杨酸受体的初步研究

水相合成了巯基丙酸(MPA)和对巯基水杨酸(MSA)双修饰的CdSe量子点，优化了量子点的合成条件并对其进行表征，探讨了量子点的毒性并成功将其应用于标记绿豆幼苗中水杨酸受体．结果表明，在pH为11.30，Cd:Se:MPA:MSA的摩尔比是1:0.5:2.5:1，反应温度为90℃时回流45min，量子点荧光强度最好；双修饰量子点分布均匀，粒径约为3-4nm；相对巯基丙酸单修饰量子点，其紫外可见吸收光谱出现红移，荧光强度明显增强，激发波长和发射波长ex/em为365/540nm；双修饰量子点的毒性比单修饰量子点有所降低；标记实验表明绿豆幼苗水杨酸受体主要存在于根部．

Synthesis of mercaptopropionic acid and mercapto salicylic acid capped CdSe Qds and preliminary study on labeling salicylic acid receptor

Abstract: In this paper we synthesized CdSe quantum dots (QDs) double capped by mercaptopropionic acid (MPA) and mercapto salicylic acid (MSA) in aqueous phase, optimized the synthesis condition of the QDs and characterised it, discussed the toxicity of the QDs and applied it to label the salicylic acid receptor of mung bean seedlings. The results showed that when the pH was 11.30, the mole ratio of Cd:Se:MPA:MSA was 1:0.5:2.5:1, the reaction temperature was 90℃ and refluxed for 45 min, the fluorescence intensity of the QDs was best; the double capped QDs was well-distributed and the particle size of which was about 3-4nm. Compared to the MPA single capped QDs, the UV-VIS absorption spectrum of the double capped QDs showed a red shift, the fluorescence strengthened obviously and the excitation and emission wavelength ex/em of which was 365/540nm. The toxicity of the double capped QDs was lower than the single capped QDs; the label experiment demonstrated that the salicylic acid receptor of mung bean seedlings exists in the root mainly, precious few in the stalk, and some in the cotyledon