RUI: Development of Novel Plasmonic Nanotransducers for Solution-based Molecular Imprinted Sensing

在化学系化学测量和成像（CMI）项目的支持下，西华盛顿大学的Ying Bao博士正在研究一类新的基于纳米颗粒的传感器的开发和实现，该传感器可以检测溶液中的微量生物分子。 金属纳米粒子，可以使其表面上有电子波的粒子被称为等离子体纳米粒子。 形成电子波的能量取决于靠近等离子体纳米颗粒表面的材料的密度。 附近材料的类型和密度的微小变化会导致电子波能量的巨大变化，这可以通过金属纳米颗粒吸收的光的能量来测量。 这种等离子体纳米粒子将通过在纳米粒子上创建以选择性方式与蛋白质结合的位置并将这些结合位点放置在纳米粒子上的位置来检测溶液中非常少量的蛋白质分子，这些位置使被吸收的光的能量发生最大变化。 这些“纳米传感器”的选择性是通过在玻璃状材料中制作分子模具或蛋白质印记来实现的。 这种分子印迹过程产生了物理上坚固且低成本的传感器，能够选择性地结合到目标分子上。 该项目将联合收割机的好处，个人等离子纳米传感器与分子印迹和开辟新的途径，在纳米传感器的发展。 在这项研究中发现的基本原理可以被研究人员应用于开发下一代新的等离子体纳米传感器，应用于临床诊断，食品安全和环境监测等领域。 该项目将为西华盛顿大学化学系的学生提供从事纳米材料相关研究并获得材料，环境和分析化学经验的机会。 此外，通过基于课程的本科研究经验（CURE）和夏季研究职位，当地社区学院的学生将获得纳米科学研究经验。为了开发和实现一类新的各向异性等离子体纳米传感器，允许基于溶液的分子印迹传感，本项目集中在三个主要目标：1）新型等离子体纳米传感器的合成和基础研究。2)在溶液中进行等离子纳米传感器的分子印迹。3)印迹纳米传感器在溶液中的传感特性研究。将使用用于在等离子体纳米棒上特定位置沉积二氧化硅的方法以及用于控制纳米级“张力”特征的生长的方法，并进一步修改以产生这种新型的各向异性等离子体纳米换能器。 这种纳米换能器的开发可以解决现有等离子体纳米材料用于基于分子印迹的传感的关键缺点，最突出的是它们在溶液中的低稳定性和有限的有效表面积。 在溶液中应用分子印迹和感测也有可能解决基于基底（平面）的系统中的重要限制，包括有限数量的印迹分子识别位点、连接到基底的传感器数量的损耗、由于纳米颗粒的固定化而降低的折射率灵敏度以及在感测系统中调节纳米传感器的数量和类型的受限灵活性。 拟议的基础研究有可能为纳米传感器和压印等离子体纳米传感器的改进设计提供有用的信息。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知识价值和更广泛的影响审查标准进行评估来支持。

With the support of the Chemical Measurement and Imaging (CMI) Program in the Division of Chemistry, Dr. Ying Bao of Western Washington University is studying the development and implementation of a new class of nanoparticle-based sensors, which detect tiny amounts of biological molecules in solution. Metal nanoparticles that can be made to have waves of electrons on their surfaces by shining light on the particles are called plasmonic nanoparticles. The energy at which the electron waves are formed is dependent on the density of materials close to the surface of the plasmonic nanoparticles. Small changes in the type and density of the nearby materials cause a large change in the energy of the electron waves, that can be measured by the energy of the light absorbed by the metal nanoparticle. Such plasmonic nanoparticles will be made to detect very small numbers of protein molecules in solution by creating locations on the nanoparticles that bind to the proteins in a selective way and by placing these binding sites at locations on the nanoparticles that give the biggest change in the energy of the light that is absorbed. The selective nature of these "nanotransducers" is being achieved by making a molecular mold or imprint of proteins in a glass-like material. This molecular imprinting process creates physically robust and low-cost sensors capable of selectively binding to target molecules. This project will combine the benefits of individual plasmonic nanotransducers with molecular imprinting and open new avenues in nanosensor development. The fundamental principles that will be discovered in this research can be applied by researchers when developing the next generation of new plasmonic nanosensors, with applications in areas such as clinical diagnosis, food safety, and environmental monitoring. The project will provide opportunities for students in the Chemistry Department at Western Washington University to engage in nanomaterial-related research and gain experience in materials, environmental, and analytical chemistry. Furthermore, through both a course-based undergraduate research experience (CURE) and summer research positions, students at a local community college will gain nanoscience research experience. To develop and implement a new class of anisotropic plasmonic nanotransducers permitting solution-based molecular imprinted sensing, this project is focused on three main objectives: 1) Synthesis and fundamental study of novel plasmonic nanotransducers. 2) Performing molecular imprinting of plasmonic nanotransducers in solution. 3) Evaluating sensing properties of imprinted nanosensors in solution. Methods for site-specific deposition of silica on plasmonic nanorods, as well as methods for controlling growth of nanoscale "tentacle" features will be used and further modified to produce this novel class of anisotropic plasmonic nanotransducer. The development of such nanotransducers could address key shortcomings of existing plasmonic nanomaterials for molecular imprint-based sensing, most prominently their low stability in solution and limited effective surface area. Applying molecular imprinting and sensing in solution also has the possibility to address important restrictions in substrate-based (planar) systems, including limited numbers of imprinted molecular recognition sites, attrition in the number of sensors connected to the substrate, reduced refractive index sensitivity due to immobilization of the nanoparticles, and restricted flexibility on adjusting the number and types of nanosensors in the sensing system. The proposed fundamental studies have the potential to provide useful information for the improved design of nano-transducers and imprinted plasmonic nanosensors.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.