Salvador María, Marqués-Fernández José Luis, Bunge Alexander, Martínez-García José Carlos, Turcu Rodica, Peddis Davide, García-Suárez María Del Mar, Cima-Cabal María Dolores, Rivas Montserrat
Department of Physics & IUTA, University of Oviedo, Campus de Viesques, 33203 Gijón, Spain.
Institute of Structure of Matter-National Research Council (CNR), 00016 Monterotondo Scalo (RM), Rome, Italy.
Nanomaterials (Basel). 2022 Jun 14;12(12):2044. doi: 10.3390/nano12122044.
Lateral flow immunoassays for detecting biomarkers in body fluids are simple, quick, inexpensive point-of-care tests widely used in disease surveillance, such as during the coronavirus disease 2019 (COVID-19) pandemic. Improvements in sensitivity would increase their utility in healthcare, food safety, and environmental control. Recently, biofunctional magnetic nanoclusters have been used to selectively label target proteins, which allows their detection and quantification with a magneto-inductive sensor. This type of detector is easily integrated with the lateral flow immunoassay format. Pneumolysin is a cholesterol-dependent cytolysin and one of the most important protein virulence factors of pneumonia produced by . It is recognized as an important biomarker for diagnosis in urine samples. Pneumonia is the infectious disease that causes the most deaths globally, especially among children under five years and adults over 65 years, most of them in low- and middle-income countries. There especially, a rapid diagnostic urine test for pneumococcal pneumonia with high sensitivity and specificity would be helpful in primary care. In this work, a lateral flow immunoassay with magnetic nanoclusters conjugated to anti-pneumolysin antibodies was combined with two strategies to increase the technique's performance. First, magnetic concentration of the protein before the immunoassay was followed by quantification by means of a mobile telephone camera, and the inductive sensor resulted in detection limits as low as 0.57 ng (telephone camera) and 0.24 ng (inductive sensor) of pneumolysin per milliliter. Second, magnetic relocation of the particles within the test strip after the immunoassay was completed increased the detected signal by 20%. Such results obtained with portable devices are promising when compared to non-portable conventional pneumolysin detection techniques such as enzyme-linked immunosorbent assays. The combination and optimization of these approaches would have excellent application in point-of-care biodetection to reduce antibiotic misuse, hospitalizations, and deaths from community-acquired pneumonia.
用于检测体液中生物标志物的侧向流动免疫测定法是简单、快速、廉价的即时检测方法，广泛应用于疾病监测，例如在2019年冠状病毒病（COVID-19）大流行期间。提高灵敏度将增加其在医疗保健、食品安全和环境控制中的效用。最近，生物功能磁性纳米团簇已被用于选择性标记目标蛋白质，这使得可以使用磁感应传感器对其进行检测和定量。这种类型的检测器很容易与侧向流动免疫测定形式集成。肺炎溶血素是一种胆固醇依赖性细胞溶素，是肺炎链球菌产生的最重要的蛋白质毒力因子之一。它被认为是尿液样本诊断的重要生物标志物。肺炎是全球导致死亡最多的传染病，尤其是在5岁以下儿童和65岁以上成年人中，其中大多数在低收入和中等收入国家。在那里，一种具有高灵敏度和特异性的肺炎球菌肺炎快速诊断尿液检测方法将有助于初级保健。在这项工作中，将与抗肺炎溶血素抗体偶联的磁性纳米团簇的侧向流动免疫测定法与两种提高该技术性能的策略相结合。首先，在免疫测定之前对蛋白质进行磁性浓缩，然后通过手机摄像头进行定量，电感式传感器的检测限低至每毫升0.57纳克（手机摄像头）和0.24纳克（电感式传感器）的肺炎溶血素。其次，免疫测定完成后在测试条内对颗粒进行磁性重新定位，使检测信号增加了20%。与酶联免疫吸附测定等非便携式传统肺炎溶血素检测技术相比，使用便携式设备获得的这些结果很有前景。这些方法的组合和优化将在即时生物检测中具有出色的应用，以减少抗生素的滥用、住院率和社区获得性肺炎导致的死亡。
