Automated target concentration, signal enhancement, and detection in a single point-of-care paper-based diagnostic

该项目的目标是开发一种易于使用的传感器设备（类似于非处方妊娠试验），以适合诊断的灵敏度检测疟疾感染。该传感器装置预计具有坚固、快速、低成本、易于解释和低检测极限的特点，同时不需要设备或训练有素的人员。主要目标是显著提高检测限，同时保持所有理想的操作特性。现有的疟疾诊断方法具有极好的敏感性和特异性，但不适合资源贫乏的环境。当前的横向流动免疫测定（LFA）设备检测乳酸脱氢酶（pLDH）、疟原虫特异性组氨酸富蛋白（HRP-2）和/或醛缩疟原虫酶，所有这些都可以在感染个体中发现，但它们的灵敏度低于世界卫生组织推荐的95%灵敏度阈值。提出的工作目标是提高传统LFA的灵敏度，通过集成两种增强方法到一个单一的，自动化的基于纸张的设备。第一种方法利用纸上的水两相系统（ATPS）分离，其中充分混合的ATPS溶液迅速分离成其宏观相，并在流过纸膜时浓缩目标生物标志物。第二种方法结合了利用具有酶活性的工程纳米颗粒的信号增强反应。这项工作将研究一种通过扩展ATPS在纸上的分离来控制流体流动的新方法，从而依次将信号增强试剂输送到LFA检测区。此外，为了最大限度地延长保质期和易用性，所有所需的分析成分都将在LFA试纸上脱水。预计，与传统LFA相比，具有预集中和信号增强功能的LFA的无缝耦合将带来显着的灵敏度，同时保持相同的用户友好性。

The goal of this project is to develop an easy to use sensor device (similar to the over-the counter pregnancy test) for the detection of malarial infection at a sensitivity suitable for diagnosis. The sensor device is expected to be robust, rapid, low-cost, easy-to-interpret and have a low detection limit while requiring no equipment or trained personnel. The primary goal is to significantly improve the detection limit while maintaining all the desirable operating characteristics. Available diagnostic methods for malaria have excellent sensitivities and specificities, but are not suitable for resource-poor settings. Current lateral-flow immunoassay (LFA) devices detect Plasmodium lactate dehydrogenase (pLDH), Plasmodium-specific histidine-rich protein (HRP-2), and/or Plasmodium aldolase, all of which are found in an infected individual, but their sensitives are below the recommended World Health Organization threshold of 95% sensitivity. The goal of the proposed work is to improve the sensitivity of the conventional LFA, by integrating two methods of enhancement into a single, automated paper-based device. The first method utilizes aqueous two-phase system (ATPS) separation on paper, in which a well-mixed ATPS solution rapidly separates into its macroscopic phases and concentrates the target biomarker as it flows through a paper membrane. The second method incorporates a signal enhancement reaction that utilizes engineered nanoparticles with enzymatic activity. The proposed work will investigate a new approach for controlling fluid flow through the extension of ATPS separation on paper in order to sequentially deliver signal enhancement reagents to the LFA detection zone. Additionally, to maximize shelf-life and ease-of-use, all required assay components will be dehydrated on the LFA test strip. It is anticipated that the seamless coupling of the LFA with pre-concentration and signal enhancement capabilities will result in significant sensitivity when compared to the traditional LFA, while maintaining the same user-friendliness.