基于HS-PEG-COOH的金纳米颗粒表面功能化及其稳定性调控机制研究-UDP糖丨MOF丨金属有机框架丨聚集诱导发光丨荧光标记推荐西安齐岳生物

HS–PEG–COOH was diluted in citrate solution while stirring at room temperature. An amount of DTT was added in the solution with molar ratio DTT/HS–PEG–COOH about 1/1. Here the DTT produces the free sulfhydryl bonds. The solution DTT–HS–PEG–COOH then was added into primary AuNPs solution while stirring at room temperature for about 15 min. The minimum amount of HS–PEG–COOH required to stabilize AuNPs was determined by the method similar to the BSA case. Two serial dilutions of the HS–PEG–COOH–AuNPs (Au@PEG) at pH=4 and pH=6.5 were prepared, varying the quantities of HS–PEG–COOH from 0 to 150 μg in 1 ml of AuNPs solution (μg ml −1), and followed by UV-VIS spectrophotometric analysis. The minimum amount of HS–PEG–COOH necessary to coat AuNPs was deduced graphically from the concentration with which the absorbance at pH=4 becomes nearly constant. All of these solutions were measured by UV-Vis spectrophotometry. The size and shape of AuNPs were characterized by a transmission electron microscope (TEM).

在室温下搅拌的同时，将HS-PEG-COOH稀释在柠檬酸盐溶液中。在溶液中加入一定量的DTT，DTT/HS–PEG–COOH的摩尔比约为1/1。在这里，DTT产生游离巯基键。然后将DTT-HS-PEG-COOH溶液加入到初级AuNP溶液中，同时在室温下搅拌约15分钟 min。稳定AuNP所需的HS-PEG-COOH的最小量是通过类似于BSA的方法确定的。

HS-PEG-COOH-AuNPs的两种系列稀释液(Au@PEG)在pH=4和pH=6.5的条件下，将HS-PEG-COOH的量从0变化到150 μg/1 ml金纳米颗粒溶液（μg ml-1），然后进行UV-VIS分光光度分析。根据pH=4时吸光度几乎恒定的浓度，以图形方式推导出涂覆AuNP所需的最小HS-PEG-COOH量。所有这些溶液都通过紫外-可见分光光度法进行了测量。通过透射电子显微镜（TEM）对金纳米颗粒的尺寸和形状进行了表征。