基于迈克尔加成反应的沙门氏菌纳米荧光标记研究

Nano-Fluorescence Labeling of Salmonella Based on Michael Addition Reaction

本文通过迈克尔加成反应的荧光标记法,成功构建了纳米荧光探针标记的沙门氏菌(YB1-INPs)。采用三(2-羧乙基)膦将沙门氏菌YB1外膜蛋白表面上的二硫键温和还原为巯基后,与吲哚菁绿(ICG)@纳米探针(INPs)的马来酰亚胺基团(Mal)交联形成YB1-INPs。通过扫描电镜和共聚焦荧光成像对YB1-INPs的形貌、光学性质进行表征。通过活死细菌染色和LB琼脂平板实验对YB1-INPs的活性进行考察。结果表明,INPs成功标记到沙门氏菌YB1表面后对YB1的形态、光学性质、活性及生长均没有产生影响,并且能够用于沙门氏菌YB1体内靶向的荧光分布成像。本研究提供的这种简单、安全、高效的荧光标记方法能够将纳米材料标记到生物载体上,可以应用于生物载体的药物输送和体内监测。

In this paper, Michael addition reaction was successfully applied to construct nano-fluorescent probe-labeled Salmonella(YB1-INPs). The mild reduction of the disulfide bond(S-S) on the outer membrane protein surface of Salmonella YB1 was achieved by tris(2-carboxyethyl) phosphine, followed by crosslinking with maleimide group(Mal) of indocyanine green(ICG)@nanoprobe(INPs). The morphological and optical properties of YB1-INPs were characterized by scanning electron microscopy(SEM) and confocal fluorescence imaging. The activity of YB1-INPs was investigated by live/dead baclight bacterial viability kit and LB agar plate test. The results showed that nanoprobe INPs were successful labeled on the surface of YB1, while this mild chemical labeling had no adverse effect on the appearance, vitality and growth rate of YB1, and could be used for the fluorescence distribution imaging of Salmonella YB1 in vivo. This simple, safe and efficient fluorescence labeling method provided by this study can label nanomaterials on biological carriers, applying to drug delivery and in vivo monitoring of biological carriers.