量子点复合纳米胶体的制备及pH传感

Preparation of Composite Quantum Dots and Nano Colloid and pH Sensing

将聚乙烯醇(PVA)作为分子骨架,与CdTe量子点和聚丙烯酸(PAA)作用形成复合纳米胶体,证明通过水相合成法可以很好地改善量子点的水溶性并避免了油相合成得到的量子点在配体交换过程中发生的荧光降低问题.研究发现,当pH值发生变化时,由于PAA质子化程度不同而导致分子伸展程度产生差异,使得量子点在PVA骨架分子中的空间位置发生了相对移动从而引起荧光性质的变化,以此建立了一种新的pH传感器.

Quantum dots are an excellent fluorescent reagent.Through the water phase synthesis method can greatly improve the water-soluble of quantum dots and avoid the reduction of fluorescence which occurred during the ligand exchange process.Along with the pH change,the protonation extent as well as the stretching degree of PAA molecules varies,resulting in the movement of the relative spatial location of QDs in the framework of hydrogels.In another word,the concentration of QDs changes in a certain space,which would induce the change of fluorescence intensity.Thereby we established a new type of nanodevice for pH sensing.