Wang Ying, Zhao Peng, Mao Leilei, Hou Yajun, Li Dawei
State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University Nanjing 210096 China
Key Lab of Cerebral Microcirculation at the Universities of Shandong, Life Science Research Centre of Taishan Medical University Taishan 271016 China.
RSC Adv. 2018 Jan 15;8(6):3143-3150. doi: 10.1039/c7ra12410d. eCollection 2018 Jan 12.
The development of rapid, highly sensitive detection methods for neuron-specific enolase (NSE) and S100-β protein is very important as the levels of NSE and S100-β protein in the blood are closely related to brain injury. Therefore, we can use NSE and S100-β protein concentration detection to realize the preliminary judgment of brain injury. In this paper, we report that a simple label-free three dimensional hierarchical plasmonic nano-architecture has been designed for the sensitive surface-enhanced Raman scattering immunosensor detection of NSE and S100-β. Owing to the active group of the hollow gold nanospheres (HAuNPs), the redox molecules 4-mercaptobenzoic acid (4-MBA) and Nile blue A (NBA) absorb antibodies and provide signal generation. The prepared HAuNPs@4-MBA and HAuNPs@NBA are used as probes to easily construct a surface-enhanced Raman scattering immunosensor. When protein biomarkers are present, the sandwich nanoparticles are captured over the substrate, forming a confined plasmonic field, leading to an enhanced electromagnetic field in intensity and in space. As a result, the Raman reporter molecules are exposed to a high density of "hot spots", which remarkably amplify the Raman signal, improving the sensitivity of the surface-enhanced Raman scattering immunosensor. Under the optimized conditions, the linear range of the proposed immunosensor is from 0.2 to 22 ng mL for both NSE and S100-β. The lowest detectable concentration is 0.1 and 0.06 ng mL for NSE and S100-β, respectively. The assay results for serum samples with the proposed method were in a good agreement with the standard enzyme-linked immunosorbent assay method. The proposed immunosensor is promising in clinical diagnosis. This method, which utilizes the surface-enhanced Raman scattering of HAuNPs, has great potential in the detection of biomarkers, which are vital in medical diagnoses and disease monitoring.
由于血液中神经元特异性烯醇化酶（NSE）和S100-β蛋白的水平与脑损伤密切相关，因此开发快速、高灵敏度的NSE和S100-β蛋白检测方法非常重要。因此，我们可以通过检测NSE和S100-β蛋白浓度来实现对脑损伤的初步判断。在本文中，我们报道了一种简单的无标记三维分级等离子体纳米结构，用于灵敏的表面增强拉曼散射免疫传感器检测NSE和S100-β。由于中空金纳米球（HAuNPs）的活性基团，氧化还原分子4-巯基苯甲酸（4-MBA）和尼罗蓝A（NBA）吸附抗体并提供信号产生。制备的HAuNPs@4-MBA和HAuNPs@NBA用作探针，可轻松构建表面增强拉曼散射免疫传感器。当存在蛋白质生物标志物时，夹心纳米颗粒在底物上被捕获，形成受限的等离子体场，导致强度和空间上的增强电磁场。结果，拉曼报告分子暴露于高密度的“热点”，这显著放大了拉曼信号，提高了表面增强拉曼散射免疫传感器的灵敏度。在优化条件下，所提出的免疫传感器对NSE和S100-β的线性范围均为0.2至22 ng/mL。NSE和S100-β的最低可检测浓度分别为0.1和0.06 ng/mL。用所提出的方法对血清样品的检测结果与标准酶联免疫吸附测定法高度一致。所提出的免疫传感器在临床诊断中具有广阔前景。这种利用HAuNPs表面增强拉曼散射的方法在生物标志物检测方面具有巨大潜力，而生物标志物在医学诊断和疾病监测中至关重要。
