Pan Xinghua, Lu Maolin, Wu Daocheng, Gai Lili
Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China.
IEEE Trans Nanobioscience. 2009 Mar;8(1):13-9. doi: 10.1109/TNB.2009.2016549. Epub 2009 Mar 16.
Quantum-dots-tagged poly (styrene-acrylamide-acrylic acid) microspheres (QDsAAMs) were synthesized and modified with hydrazine hydrate through hydrazinolysis. Azidocarbonyl groups, which can be rapidly coupled with proteins under mild conditions, were introduced onto the surface of QDsAAM using azido reaction. Bovine serum albumin (BSA) was selected as model protein to be covalently immobilized on the azidocarbonyl QDsAAM. Instruments such as fluorescence microscope, optical microscope, confocal laser scanning microscope, UV-visible spectrometer, Fourier transform infrared spectrometer, size analyzer, and fluorescence spectrophotometer were used to characterize QDsAAM. Results showed that QDsAAM had a regular double-layer spherical shape and an average diameter of 11.2 microm. It also displayed high fluorescence intensity (lambda(ex)/lambda(em) = 250 nm/370 nm), which showed linearity with concentrations ranging from 3.0 x10(-3) to 90.0 x10(-3) g.L(-1). In addition, external factors such as pH and ionic strength exerted little influence on fluorescent characteristic. BSA immobilization indicated that QDsAAM with azidocarbonyl groups could be covalently coupled with BSA at the rate of 40 x10(-3) g/g (BSA/QDsAAM), while fluorescence linearity correlation was also found. This functional azidocarbonyl QDsAAM with sensitive fluorescence and active azidocarbonyl groups could be used as a promising fluorescent probe for quantitative detection, protein immobilization, and early rapid clinical diagnostics.
合成了量子点标记的聚（苯乙烯 - 丙烯酰胺 - 丙烯酸）微球（QDsAAMs），并通过水合肼肼解对其进行修饰。利用叠氮反应将可在温和条件下与蛋白质快速偶联的叠氮羰基基团引入到QDsAAM表面。选择牛血清白蛋白（BSA）作为模型蛋白，将其共价固定在叠氮羰基QDsAAM上。使用荧光显微镜、光学显微镜、共聚焦激光扫描显微镜、紫外可见光谱仪、傅里叶变换红外光谱仪、粒度分析仪和荧光分光光度计等仪器对QDsAAM进行表征。结果表明，QDsAAM具有规则的双层球形形状，平均直径为 11.2微米。它还显示出高荧光强度（激发波长/发射波长 = 250纳米/370纳米），在浓度范围为3.0×10（-3）至90.0×10（-3）克·升（-1）时呈线性关系。此外，pH值和离子强度等外部因素对荧光特性影响很小。BSA固定表明，带有叠氮羰基基团的QDsAAM可以以40×10（-3）克/克（BSA/QDsAAM）的速率与BSA共价偶联，同时也发现了荧光线性相关性。这种具有灵敏荧光和活性叠氮羰基基团的功能性叠氮羰基QDsAAM可作为一种有前景的荧光探针用于定量检测、蛋白质固定和早期快速临床诊断。
