Song Chi, Luo Haoyue, Lin Xiaogang, Peng Zhijia, Weng Lingdong, Tang Xiaosheng, Xu Shibin, Song Ming, Jin Lifeng, Zheng Xiaodong
Department of Life Science and Technology, Changshu Institute of Technology, Changshu, China.
Key Laboratory of Optoelectronic Technology and Systems of Ministry of Education of China, Chongqing University, Chongqing, China.
Front Chem. 2020 May 5;8:331. doi: 10.3389/fchem.2020.00331. eCollection 2020.
In recent years, non-toxic quantum dot has caught the attention of biomedical fields. However, the inherent cytotoxicity of QDs makes its biomedical application painful, and is a major drawback of this method. In this paper, a non-toxic and water-soluble quantum dot AgInZnS-GO using graphene oxide was synthesized. A simple model of state complex was also established, which is produced through a combination of quantum dots and protein. The interaction between AIZS-GO QDs and human serum albumin (HSA) has significant meaning biological application. Herein, the binding of AIZS-GO QDs and HSA were researched using fluorescence spectra, Uv-visible absorption spectra, FT-IR spectra, and circular dichroism (CD) spectra. The results of fluorescence spectra demonstrate that AIZS-GO QDs have an obvious fluorescence quenching effect on HSA. The quenching mechanism is static quenching, which implies that some type of complex was produced by the binding of QDs and HSA. These results were further proved by Uv-visible absorption spectroscopy. The Stern-Volmer quenching constant K at various temperatures (298 K, 303 K, 308 K) were acquired from analyzing Stern-Volmer plots of the fluorescence quenching information. The Van't Hoff equation could describe the thermodynamic parameters, which demonstrated that the van der Waals and hydrogen bonds had an essential effect on the interaction. FT-IR spectra and CD spectra further indicate that AIZS-GO QDs can alter the structure of HSA. These spectral methods show that the quantum dot can combine well with HSA. The experimental results showed that AgInZn-GO water-soluble quantum dots have good biocompatibility, which can be combined with proteins to form new compounds which have no cytotoxicity and biological practicability. It provides an important basis for the combination of quantum dots and specific proteins as well as fluorescent labeling.
近年来，无毒量子点引起了生物医学领域的关注。然而，量子点固有的细胞毒性使其在生物医学应用中面临困境，这是该方法的一个主要缺点。本文合成了一种使用氧化石墨烯的无毒水溶性量子点AgInZnS-GO。还建立了一个简单的状态复合体模型，它是通过量子点与蛋白质结合产生的。AIZS-GO量子点与人血清白蛋白（HSA）之间的相互作用在生物应用中具有重要意义。在此，利用荧光光谱、紫外可见吸收光谱、傅里叶变换红外光谱（FT-IR）和圆二色性（CD）光谱研究了AIZS-GO量子点与HSA的结合。荧光光谱结果表明，AIZS-GO量子点对HSA有明显的荧光猝灭作用。猝灭机制为静态猝灭，这意味着量子点与HSA结合产生了某种类型的复合物。紫外可见吸收光谱进一步证明了这些结果。通过分析荧光猝灭信息的Stern-Volmer图，获得了不同温度（298K、303K、308K）下的Stern-Volmer猝灭常数K。范特霍夫方程可以描述热力学参数，这表明范德华力和氢键对相互作用有重要影响。FT-IR光谱和CD光谱进一步表明，AIZS-GO量子点可以改变HSA的结构。这些光谱方法表明量子点可以与HSA很好地结合。实验结果表明，AgInZn-GO水溶性量子点具有良好的生物相容性，可与蛋白质结合形成无细胞毒性且具有生物实用性的新化合物。它为量子点与特定蛋白质的结合以及荧光标记提供了重要依据。
