Fathi Farzaneh, Jalili Roghayeh, Amjadi Mohammad, Rashidi Mohammad-Reza
Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Sciences, Tabriz, Iran.
Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran.
Bioimpacts. 2019;9(2):71-78. doi: 10.15171/bi.2019.10. Epub 2018 Oct 20.
The detection of micrometer-sized particles like cells is limited by surface plasmon resonance (SPR) biosensors because of having a depth of evanescent wave <500 nm. In this study, for the first time, we exhibited the use of streptavidin-functionalized gold nanorods (GNRs) as intensification labels for detection of cell surface markers in SPR-based biosensors. The GNRs (ʎ max: 735 nm) were modified with streptavidin using EDC/NHS coupling method and human umbilical vein endothelial cells (HUVECs) were selected as the cell model for detecting VE-cadherin on cell surface using real-time SPR device in the 785 nm wavelength of the laser source. The investigations revealed that the plasmonic field extension produced from the gold layer and GNRs resulted in multiple enhancement of SPR signals when the wavelength of laser source in SPR instrument was matched with the wavelength of maximum absorbance in GNRs. Moreover, the results showed that the growth of ∆RU value in specific and non-specific bindings for various cell number injections were produced with increasing the cell number. The results displayed that cell detection can be performed in real- time form without any need to a time-consuming process used in conventional methods like immunocytochemistry, flow cytometry, and western blotting.
由于倏逝波深度小于500 nm，表面等离子体共振（SPR）生物传感器对细胞等微米级粒子的检测存在局限性。在本研究中，我们首次展示了使用链霉亲和素功能化的金纳米棒（GNRs）作为增强标记物，用于基于SPR的生物传感器中细胞表面标志物的检测。使用EDC/NHS偶联方法用链霉亲和素修饰GNRs（λmax：735 nm），并选择人脐静脉内皮细胞（HUVECs）作为细胞模型，在785 nm激光源波长下使用实时SPR装置检测细胞表面的血管内皮钙黏蛋白（VE-cadherin）。研究表明，当SPR仪器中的激光源波长与GNRs中的最大吸收波长匹配时，金层和GNRs产生的等离子体场扩展导致SPR信号多次增强。此外，结果表明，随着细胞数量的增加，不同细胞数量注入时特异性和非特异性结合中ΔRU值的增长也随之产生。结果显示，可以以实时形式进行细胞检测，而无需像免疫细胞化学、流式细胞术和蛋白质印迹等传统方法中那样耗时的过程。
