CdS量子点的制备及细胞膜初步荧光标记

Synthesis of aqueous CdS nano-crystals and rough fluorescence labeling of onion inner pellicle cell

以巯基乙酸为稳定剂,通过控制反应温度、反应时间及pH值,在水相中合成了稳定的受激发出紫光、蓝光、绿光、黄光和红光的CdS量子点;通过紫外可见吸收光谱、荧光光谱和X射线衍射谱(XRD)对产物的光学性能和晶体结构进行了表征,结果表明所合成的CdS量子点分散性较好,量子产率为8%,为立方晶型,粒径约1 nm;利用荧光倒置显微镜观察了量子点在洋葱内表皮细胞膜上聚集及受激发射荧光行为,实现细胞膜初步标记。

A series of aqueous colloidal CdS nano-crystals were synthesized by using thioglyeolic acid as a stabilizer and only controlling of preparation temperature, reaction time and pH value without adding any buffer solution. The color of emission varies from violet to red. The optical properties of as-prepared CdS quantum dots were studied by its fluorescence emission, excitation and UV-vis absorption spectra. The emission wavelength of these CdS quantum dots ranged from 370 run to 600 nm, its excitation wavelength could range from 200 mm to 420 nm, and its photoluminescence （PL） full width of half-maximum was about 100 nm, the PL quantum yield was up to 8% compared to rhodamine 6 G. Experimental results showed that both pH value and preparation temperature have impact on resultant emission wavelength, reaction time could affect resultant PL intensity. The diameter of cubic CdS was about 1 nm, supported by the characteristic X-my diffraction （XRD）. With the help of fluorescence microscope, the aggregation of CdS and their emission fluorescence around the membrane of onion inner peUicle cell were observed, indicated that the cell membrane was labeled by the nano-crystals.