A New Design of Nanoscale Optical Voltage Sensors from Plasmonic/Nonlinear-Optical Material Core/Shell Nanoparticles

在化学系化学测量和成像计划的支持下，加州大学洛杉矶分校的段教授设计和开发了新一代纳米级光学电压传感器(NOVS)，该传感器基于具有等离子体纳米结构核心和非线性光学(NLO)材料外壳的核/壳纳米粒子。等离子体/NLO核/壳纳米粒子的设计创造了一种新的信号通路，可以灵敏而快速地将局部电压信号转换为可检测的光信号。本项目致力于设计、合成和研究所描述的核/壳纳米粒子的光电传感器，并探索将优化后的传感器用于监测细胞膜电位的可行性。电压信号光学记录器的设计具有广泛的应用前景，特别是对于记录高通量、高空间和时间分辨率所必需的细胞膜电位具有重要意义。这类应用可以用来检查神经回路，这是大脑活动的一个组成部分。根据美国国家科学基金会的“了解大脑”计划，所描述的NOVS的成功开发可能会极大地扩展我们检测、成像和监测动态神经活动的能力，以提供对大脑功能的洞察。段教授的研究计划与教育和推广活动紧密结合，广泛传播研究成果。他的项目为学生提供教育和培训机会。他还与加州纳米系统研究所合作，帮助培训高中教师将新的纳米技术概念带到他们的高中科学课程中。段教授正在开发纳米级光学电压传感器(NOVS)，该传感器由具有等离子体纳米结构的核/壳纳米粒子和非线性光学(NLO)材料的壳组成。他使用外部电场来主动调制介电环境，从而调节其等离子体共振光谱，从而创建了一种新的信号通路，以灵敏而快速地将本地电压信号转换为可检测的光学信号。本项目包括五项研究和教育活动：(1)使用有限元模拟来指导设计一系列具有所需等离子体性质和电光调制的等离子体/非线性光学核/壳纳米结构；(2)开发稳健的化学方法来合成成分、形貌、尺寸和等离子体共振性质可控的等离子体核；(3)利用单粒子光谱来研究所设计的核/壳纳米粒子的电光调制和电压灵敏度；(4)探索利用优化的NOVS来监测细胞膜电位的可行性；(5)将荧光材料与等离子体/NLO纳米粒子相结合，将基于散射的等离子体信号转换为荧光信号。

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry, Professor Duan at University of California, Los Angeles, designs and develops a new generation of nanoscale optical voltage sensors (NOVS) based on core/shell nanoparticles with a core of plasmonic nanostructure and a shell of nonlinear-optical (NLO) material. The design of plasmonic/NLO core/shell nanoparticles creates a new signaling pathway to sensitively and rapidly convert the local voltage signal into a detectable optical signal. This project focuses on designing, synthesizing and investigating the electro-optical sensor of described core/shell nanoparticles, and exploring the feasibility of using the optimized sensors for monitoring cell membrane potential. The design of optical reporters of voltage signal is of considerable interest for diverse applications, particularly for recording cell membrane potentials that are essential for high throughput, high space and time resolution. Such applications can be used to examine neural circuits, an integral component of brain activities. In line with the NSF "Understand the Brain" initiative, the successful development of the described NOVS may greatly expand our capability in detecting, imaging and monitoring dynamic neural activities to provide insight on brain function. Professor Duan's research program is closely integrated with education and outreach activities to broadly disseminate the research results. His program provides students with educational and training opportunities. He also works with the California NanoSystems Institute to help training high school teachers to bring new nanotechnology concepts to their high school science classes.Professor Duan is developing nanoscale optical voltage sensors (NOVS) consisting of a core/shell nanoparticles with a core of plasmonic nanostructure and a shell of nonlinear-optical (NLO) material. He uses an external electrical field to actively modulate the dielectric environment and thus its plasmonic resonance spectrum, creating a new signaling pathway to sensitively and rapidly transfer the local voltage signal into a detectable optical signal. This project includes five research and educational activities: (1) to use finite element simulation to guide the design of a series of plasmonic/NLO core/shell nanostructures with desired plasmonic properties and electro-optical modulation; (2) to develop robust chemistries to synthesize the plasmonic core with controlled composition, morphology, dimension and the plasmonic resonance properties; (3) to use single particle spectroscopy to investigate the electro-optical modulation and the voltage sensitivity of the designed core/shell nanoparticles; (4) to explore the feasibility of using the optimized NOVS for monitoring cell membrane potential; and (5) to integrate fluorescence materials with the plasmonic/NLO nanoparticles to convert scattering-based plasmonic signal to fluorescence signal.