Nanomedicine and Nanotoxicology Group, São Carlos Institute of Physics , University of São Paulo , 13560-970 São Carlos , SP , Brazil.
Department of NanoEngineering , University of California, San Diego , La Jolla , California 92093 , United States.
ACS Nano. 2019 Nov 26;13(11):13325-13332. doi: 10.1021/acsnano.9b06571. Epub 2019 Nov 4.
Alzheimer's disease is a devastating condition characterized by a progressive and slow brain decay in elders. Here, we developed a paper-based lateral flow immunoassay for simultaneous and fast determination of Alzheimer's blood biomarkers, fetuin B and clusterin. Selective antibodies to targeted biomarkers were immobilized on gold nanoparticles (AuNPs) and deposited on paper pads. After adding the sample on the paper-based device, the biofluid laterally flows toward the selective antibody, permitting AuNP-Ab accumulation on the test zone, which causes a color change from white to pink. Image analysis was performed using a customized algorithm for the automatic recognition of the area of analysis and color clustering. Colorimetric detection was compared to electrochemical methods for the precise quantification of biomarkers. The best performance was found for the color parameter "*". Good linearity ( = 0.988 and 0.998) and reproducibility (%RSD = 2.79% and 1.82%, = 3) were demonstrated for the quantification of fetuin B and clusterin, respectively. Furthermore, the specificity of the immunosensor was tested on mixtures of proteins, showing negligible cross-reactivity and good performance in complex environments. We believe that our biosensor has a potential for early-stage diagnosis of Alzheimer's disease and toward a better understanding of Alzheimer's developing mechanisms.
阿尔茨海默病是一种破坏性疾病，其特征是老年人的大脑进行性和缓慢衰退。在这里，我们开发了一种基于纸张的侧向流动免疫分析方法，用于同时快速测定阿尔茨海默病的血液生物标志物胎球蛋白 B 和簇蛋白。针对靶向生物标志物的选择性抗体被固定在金纳米粒子（AuNPs）上，并沉积在纸垫上。在将样品添加到基于纸张的设备后，生物流体向选择性抗体侧向流动，允许 AuNP-Ab 在测试区域积累，从而导致颜色从白色变为粉红色。使用自定义算法进行图像分析，用于自动识别分析区域和颜色聚类。与电化学方法相比，比色检测可更精确地定量生物标志物。对于颜色参数“*”，可以获得最佳性能。对于胎球蛋白 B 和簇蛋白的定量，分别表现出良好的线性（= 0.988 和 0.998）和重现性（%RSD = 2.79% 和 1.82%， = 3）。此外，还在蛋白质混合物上测试了免疫传感器的特异性，显示出可忽略的交叉反应性和在复杂环境中的良好性能。我们相信，我们的生物传感器有可能用于阿尔茨海默病的早期诊断，并更好地了解阿尔茨海默病的发展机制。
