Bioengineering, Cancer Center at Illinois , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801 , United States.
Anal Chem. 2019 Feb 19;91(4):2876-2884. doi: 10.1021/acs.analchem.8b04848. Epub 2019 Jan 29.
We report on a magnetic focus lateral flow biosensor (mLFS) for ultrasensitive detection of protein biomarkers in a practical format. With valosin-containing protein as a target protein, we show that the developed mLFS concept could detect as low as 25 fg/mL with magnetic focus to enhance target capture efficiency to deliver a 10-fold improvement in sensitivity compared to that of conventional lateral flow (LF) systems. The conceptualized strategy utilizes a simple magnet placed beneath the three-dimensional printed LF device to concentrate the targets at the signal zone without any additional instrumentation. In addition, protein mixtures extracted from the tissue of cervical cancer patients was also utilized to validate the sensor. To investigate the effect of magnetic focus on sensitivity, surface-enhanced Raman spectroscopy and dark-field imaging was utilized to characterize the distribution and movement of FeO core-Au shell nanoprobes in a model LF strip. Our experiments show that the magnetic focus results in an increased interaction time between the magnetic probe-labeled targets and the capture antibody, yielding a higher capture efficiency, allowing for ultrasensitive detection of the target not possible before with LF. The proposed mLFS can be utilized to detect a range of trace protein biomarkers for early diagnosis and can be combined with diverse pretreatment and signal amplification steps to query complex samples.
我们报告了一种用于超灵敏检测蛋白质生物标志物的磁性聚焦横向流动生物传感器（mLFS），采用实用格式。以包含缬氨酸蛋白的蛋白作为靶蛋白，我们表明，所开发的 mLFS 概念可以检测到低至 25 fg/mL 的浓度，通过磁性聚焦提高目标捕获效率，与传统的横向流动（LF）系统相比，灵敏度提高了 10 倍。所构想的策略利用放置在三维打印 LF 装置下方的简单磁铁将目标集中在信号区域，而无需任何额外的仪器。此外，还利用从宫颈癌患者组织中提取的蛋白质混合物来验证传感器。为了研究磁性聚焦对灵敏度的影响，利用表面增强拉曼光谱和暗场成像来表征模型 LF 条带中 FeO 核-Au 壳纳米探针的分布和运动。我们的实验表明，磁性聚焦导致磁性探针标记的靶标与捕获抗体之间的相互作用时间增加，从而提高了捕获效率，实现了 LF 之前不可能实现的对靶标的超灵敏检测。所提出的 mLFS 可用于检测一系列痕量蛋白质生物标志物，用于早期诊断，并可与多种预处理和信号放大步骤结合使用，以查询复杂样本。
