Collaborative Research: An Enzyme-free Amplification Technique for Ultrasensitive ELISA of Disease Biomarkers

疾病诊断技术对提高我们的生活水平至关重要。提高诊断技术的检测灵敏度可以实现疾病的早期诊断，特别是癌症和传染病，从而改善治疗结果。该项目的目标是通过开发基于纳米颗粒的信号放大技术建立一个高灵敏度的诊断平台。该研究计划的更广泛影响包括为研究生和本科生（特别是来自代表性不足群体的学生）提供多学科培训，以及指导当地高中生和两个研究所之间的夏季学生交流等外联活动。酶联免疫吸附测定（ELISA）技术已广泛应用于研究实验室和临床诊断数十年。然而，近年来其检测限并没有得到实质性的提高。本研究旨在开发一种新的无酶信号放大技术，以提高ELISA的检测灵敏度。这项技术依赖于释放数百万个预装在金囊泡中的微小纳米颗粒。每个释放的纳米颗粒可以比ELISA中常用的酶更有效地催化比色反应。通过用这种纳米颗粒包封的金囊泡取代常规ELISA中的酶，建立了具有显著增强的灵敏度的无酶ELISA。为了优化信号放大系统，从而提高检测灵敏度的相关酶无ELISA，纳米粒子和金囊泡的物理化学性质将被仔细控制。为实现本课题的研究目标，本课题将开展以下研究工作：1）构建基于纳米颗粒的信号放大系统; 2）建立无酶ELISA方法; 3）将无酶ELISA方法应用于加标生物标志物标准品的人血样品检测。信号放大技术预计将影响体外诊断的一般领域，并在生物医学中找到广泛的应用。该项目将有利于研究生和本科生，特别是妇女和少数民族参与研究。这项研究也将被纳入K-12学生的外展活动中。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

Technologies for diagnosis of diseases are essential to the improvement of our standard of living. Increasing detection sensitivity of a diagnostic technology can enable earlier diagnosis of diseases especially cancers and infectious diseases, thus improving treatment outcomes. The goal of this project is to establish a highly sensitive diagnostic platform through the development of a nanoparticle-based signal amplification technique. The broader impacts of the proposed research program include multidisciplinary training for graduate and undergraduate students particularly from underrepresented groups, as well as outreach activities such as mentoring local high-school students and student exchange between two institutes in summer.Enzyme-linked immunosorbent assay (ELISA) technology has been extensively used in research labs and clinical diagnostics for decades. However, its limit of detection has not been substantially improved in recent years. The proposed work seeks to develop a novel enzyme-free signal amplification technique that can substantially enhance the detection sensitivity of ELISA. This technique relies on the release of millions of tiny nanoparticles preloaded in gold vesicles. Each released nanoparticle can catalyze colorimetric reaction more effectively than a commonly-used enzyme in an ELISA. By substituting enzymes in a conventional ELISA with such nanoparticles-encapsulated gold vesicles, an enzyme-free ELISA with substantially enhanced sensitivity is established. To optimize the signal amplification system and thus enhance the detection sensitivity of associated enzyme-free ELISA, physicochemical properties of both nanoparticles and gold vesicles will be carefully controlled. To achieve the goal of this project, following research aims will be pursued: 1) Building the nanoparticles based signal amplification system; 2) Establishing the enzyme-free ELISA; and 3) Applying the enzyme-free ELISA to detecting human blood samples spiked with biomarker standards. The signal amplification technique is expected to impact the general field of in-vitro diagnostics and find a broad range of applications in biomedicine. This project will benefit the engagement of graduate and undergraduate students, especially women and minorities, into research. The research will also be integrated into outreach activities for K-12 students.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.