Institute of Analytical Chemistry, Czech Academy of Sciences, Brno, Czech Republic.
Central European Institute of Technology, Brno University of Technology, Brno, Czech Republic.
Methods Mol Biol. 2020;2135:55-83. doi: 10.1007/978-1-0716-0463-2_3.
The implementation of quantum dots in analytical chemistry has already advanced from basic research activities to routine applications of commercially available fluorescent agents present in sophisticated assays kits. Nevertheless, a further development of new preparation and characterization methods of nanoparticles is still required to increase the sensitivity of analytical methods substantially. Thus, in many bioanalytical applications, important molecules such as DNA, proteins, and antibodies are routinely conjugated with fluorescent tags to reach even the absolute sensitivity, that is, the capability to detect a single molecule in complex matrices. Semiconductor quantum dots have already proved to be suitable components of highly luminescent tags, probes, and sensors with broad applicability in analytical chemistry. Quantum dots provide high extinction coefficients together with wide ranges of excitation wavelengths, size- and composition-tunable emissions, narrow and symmetric emission spectra, good quantum yields, relatively long size-dependent luminescence lifetime, and low photobleaching. Most of these properties are superior when compared with conventional organic fluorescent dyes. In this chapter, optimized procedures for the preparation of water-dispersed CdTe quantum dots; their coatings and conjugation reactions with antibodies, DNA, and macrocycles; and their analyses by capillary electrophoresis are described. The potential of capillary electrophoresis for fast analyses of nanoparticles, their conjugates with antibodies and immunocomplexes with targeted antigens, is demonstrated as an example.
量子点在分析化学中的应用已经从基础研究活动发展到了商业上可利用的荧光试剂在复杂分析试剂盒中的常规应用。然而，仍然需要进一步开发新的纳米粒子制备和表征方法，以大大提高分析方法的灵敏度。因此，在许多生物分析应用中，DNA、蛋白质和抗体等重要分子通常与荧光标记物结合，以达到甚至绝对的灵敏度，即能够在复杂基质中检测单个分子的能力。半导体量子点已被证明是高发光标记物、探针和传感器的合适组件，在分析化学中有广泛的应用。量子点提供了高消光系数以及宽的激发波长范围、尺寸和组成可调的发射、窄而对称的发射光谱、良好的量子产率、相对较长的尺寸依赖性发光寿命和低的光漂白。与传统的有机荧光染料相比，这些特性大多数都更为优越。本章描述了制备水相分散的 CdTe 量子点的优化程序；它们的涂层和与抗体、DNA 和大环的缀合反应；以及通过毛细管电泳进行的分析。作为一个例子，展示了毛细管电泳在快速分析纳米粒子及其与抗体的缀合物以及与靶向抗原的免疫复合物方面的潜力。
