Plasmon-Controlled Fluorescence and Cardiac Markers

描述(由申请人提供)：我们建议继续研究用于快速高灵敏度诊断的金属纳米结构的开发，特别是不需要扩增步骤的心脏标志物阵列。我们选择心脏标记物作为目标分析对象，因为它们具有很强的医学意义。冠心病(CHD)是包括美国在内的发达国家的主要死亡原因。据估计，每年有800万名患者急诊入院，出现缺血性心脏病和心肌梗死(MI)的症状。无论是开始使用抗凝剂进行快速治疗，还是确定症状没有危险，快速诊断都是必不可少的。朝着这个方向，我们的方法结合了等离子体激元和纳米光学的新兴科学，以提高临床测试的荧光灵敏度。在目前的三年获奖周期中，我们已经实现了之前提出的大部分金属结构测试目标，包括颗粒尺寸不均匀分布的金属岛膜、连续金属膜、电子束光刻制备的有序纳米颗粒阵列和聚焦离子束(FIB)制备的纳米孔阵列。使用这些结构，我们已经达到了肌红蛋白所需的临床灵敏度目标，并且在不使用生化扩增步骤的情况下，其灵敏度与B型钠尿肽(BNP)和心肌肌钙蛋白I(CTnI)所需的灵敏度相差10倍。我们注意到cTnl要求的低检测下限为0.22 pm。这些结果表明，将金属纳米结构用于临床检测具有很高的潜力。在 目前的建议是，我们将重点放在金属结构的开发上，这将使灵敏度额外提高100倍。我们选择这个目标是为了确保这些结构达到或超过临床要求。我们将专注于易于制备并引入临床实验室的纳米结构。出于这些原因，我们建议开发可以使用自下而上的批量化学方法来制备的结构，而不需要自上而下的纳米制造技术。我们的建议如下：1.开发和优化由金属颗粒、介电隔离物和连续金属膜组成的多层底物，用于高灵敏度的临床分析。这些底物将在临床检测条件下进行重复性和稳定性测试。2.将这些金属纳米结构用于心脏标志物肌球蛋白、心肌肌钙蛋白I(CTnI)和B型利钠肽(BNP)的检测，无需扩增步骤，即可满足临床需要。所提出的层状纳米结构为高荧光增强和背景排斥提供了机会。我们将把结果与临床样本和已知标准进行比较。3.在金属层上使用水凝胶波导为下一代分析开发基质。这些结构为在简单的多层器件中实现有效的定向发射和波长分离提供了机会。

DESCRIPTION (provided by applicant): We propose to continue our studies on the development of metallic nanostructures for rapid high-sensitivity diagnostics, and in particular arrays for cardiac markers without amplifications steps. We selected cardiac markers as the target analytes because of their strong medical importance. Coronary heart disease (CHD) is the leading cause of mortality in developed countries including the USA. Each year an estimated 8 million patients admit acutely to emergency rooms with symptoms suggestive of ischemic heart disease and myocardial infarction (MI). Rapid diagnosis is essential either to initiate rapid treatment with anti-coagulants or to determine the symptoms are non-threatening. Towards this direction our approach combines the emerging sciences of plasmonics and nano-optics to increase the sensitivity of fluorescence for clinical testing. During the present three year award cycle, we have accomplished a majority of the previously proposed Aims for testing of metallic structures including metal island films with heterogeneous distribution of particle sizes, continuous metal films, well-ordered nanoparticle arrays fabricated by e-beam lithography and nanohole arrays by a focused ion beam (FIB). Using these structures we have reached the needed clinical sensitivity goals for myoglobin, and are within a factor of 10 of the sensitivity needed for B-type natriuretic peptide (BNP) and cardiac troponin I (cTnl), without using biochemical amplification steps. We note that the cTnl requires a low detection limit of 0.22 pM. These results indicate the high potential of using metal nanostructures for clinical assays. In the current proposal we focus on the development of metallic structures which can provide an additional 100-fold increase in sensitivity. We selected this goal to insure these structures meet or exceed the clinical requirements. We will focus on nanostructures which can be easily prepared and introduced into clinical laboratories. For these reasons we propose to develop structures which can be prepared using bottom-up batch chemical methods, without the need for top-down nanofabrication technology. We propose the following: 1. Develop and optimize multi-layer substrates consisting of metal particles, a dielectric spacer and a continuous metal film for high sensitivity clinical assays. The substrates will be tested for reproducibility and stability under clinical assay conditions. 2. Use these metallic nanostructures for cardiac markers assays for myogloblin, cardiac troponin I (cTnI) and B-type natriuretic peptide (BNP) which satisfy the clinical needs without amplification steps. The proposed layered nanostructures provide opportunities for high fluorescence enhancements and background rejection. We will compare the results with clinical samples and known standards. 3. Develop substrates for the next generation of assays using hydrogel waveguides on metallic layers. These structures offer the opportunity for efficient directional emission and wavelength separation in a simple multi-layer device.