Laboratorio de Microbiología Molecular, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile.
PLoS One. 2012;7(1):e30741. doi: 10.1371/journal.pone.0030741. Epub 2012 Jan 23.
Multiple applications of nanotechnology, especially those involving highly fluorescent nanoparticles (NPs) or quantum dots (QDs) have stimulated the research to develop simple, rapid and environmentally friendly protocols for synthesizing NPs exhibiting novel properties and increased biocompatibility. In this study, a simple protocol for the chemical synthesis of glutathione (GSH)-capped CdTe QDs (CdTe-GSH) resembling conditions found in biological systems is described. Using only CdCl(2), K(2)TeO(3) and GSH, highly fluorescent QDs were obtained under pH, temperature, buffer and oxygen conditions that allow microorganisms growth. These CdTe-GSH NPs displayed similar size, chemical composition, absorbance and fluorescence spectra and quantum yields as QDs synthesized using more complicated and expensive methods.CdTe QDs were not freely incorporated into eukaryotic cells thus favoring their biocompatibility and potential applications in biomedicine. In addition, NPs entry was facilitated by lipofectamine, resulting in intracellular fluorescence and a slight increase in cell death by necrosis. Toxicity of the as prepared CdTe QDs was lower than that observed with QDs produced by other chemical methods, probably as consequence of decreased levels of Cd(+2) and higher amounts of GSH. We present here the simplest, fast and economical method for CdTe QDs synthesis described to date. Also, this biomimetic protocol favors NPs biocompatibility and helps to establish the basis for the development of new, "greener" methods to synthesize cadmium-containing QDs.
纳米技术的多种应用，特别是涉及高荧光纳米粒子（NPs）或量子点（QDs）的应用，刺激了研究人员开发简单、快速和环保的协议，以合成具有新颖性质和增加生物相容性的 NPs。在本研究中，描述了一种简单的协议，用于化学合成谷胱甘肽（GSH）封端的 CdTe QDs（CdTe-GSH），类似于生物系统中发现的条件。仅使用 CdCl(2)、K(2)TeO(3)和 GSH，在允许微生物生长的 pH、温度、缓冲液和氧气条件下，获得了高荧光 QDs。这些 CdTe-GSH NPs 显示出相似的尺寸、化学成分、吸收和荧光光谱以及量子产率，与使用更复杂和昂贵方法合成的 QDs 相同。CdTe-GSH NPs 不易自由进入真核细胞，因此有利于其生物相容性和在生物医学中的潜在应用。此外，通过脂质体促进 NPs 的进入，导致细胞内荧光，并通过坏死导致细胞死亡略有增加。所制备的 CdTe QDs 的毒性低于用其他化学方法制备的 QDs，这可能是由于 Cd(+2)水平降低和 GSH 含量增加所致。我们在这里介绍了迄今为止描述的最简单、快速和经济的 CdTe QDs 合成方法。此外，这种仿生协议有利于 NPs 的生物相容性，并有助于为开发新的、“更环保”的合成含镉 QDs 的方法奠定基础。
