ZnS量子点的生物合成及对阿萨尔基亚芽胞杆菌的标记

Biosynthesis of ZnS quantum dot and its application in biolabeling Bacillus axarquiensis

通过微生物合成金属量子点是目前研究的热点。本研究通过白色念珠菌合成ZnS量子点,对合成的量子点用高分辨透射电镜(HR-TEM)和X射线衍射(XRD)进行表征,用生物合成的ZnS量子点标记生防菌阿萨尔基亚芽胞杆菌,为建立生防菌阿萨尔基亚芽胞杆菌的荧光探针标记提供科学依据。实验结果表明,ZnSO4浓度为20 mmol/L时白色念珠细胞内合成ZnS量子点,通过反复冻融破细胞壁提出胞内ZnS量子点,紫外-可见光谱(UV)检测ZnS量子点在348 nm处显示有吸收带,HR-TEM测其粒径约7. 06 nm,荧光分光光谱分析量子点激发波在280 nm和363 nm,XRD显示ZnS量子点特征峰。ZnS量子点中加入1-乙基-3-(3-二甲基氨丙基)-碳化二亚胺(EDC)和N-羟基琥珀酰亚胺(NHS)偶联剂的芽胞杆菌样本的标记效率明显高于不加偶联剂的样本。白色念珠菌合成的ZnS量子点可以用于微生物标记。

The development of reliable and eco-friendly processes for the synthesis of metal sulphide quantum dots has been considered as a major challenge in the field of nanotechnology. In the present study,ZnS quantum dots were synthesized through Candida albicans. The ZnS quantum dots were further characterized using high-resolution transmission electron microscope(HR-TEM)and X-ray diffraction(XRD). The results confirmed that intracellular ZnS quantum dots were produced by a facile procedure and freeze thaw extraction using 20 mmol/L ZnS quantum dots. The ZnS quantum dots showed surface plasmon resonance band at 348 nm. The size of ZnS quantum dots was 10 nm. Photoluminescence spectra excited at 280 nm and 363 nm revealed quantum confinement effects. Powder X-ray diffraction(XRD)analysis revealed that the nanoparticles were in the sphalerite phase. B. axarquiensis labeling efficiency was significantly higher when incubated with carbodiimine hydrochloride(EDC)and n-hydroxysuccinimide(NHS)coupling agent. ZnS quantum dots synthesized by C. albicans may have great potential in microbial labeling.