纳米金局域表面等离子体共振增强光电化学传感的研究

Nano-sized noble metal plasmonics have been a hot research in the field of photovoltaics since they can efficiently focuse energy and enhance the concentration of photoexcitons and also help promoting the seperation of the carriers. In order to overcome the disadvantages of the carrier recombination to improve the detection sensitivity, the localized surface plasmon resonance of nano-sized Au in photoelectrochemical sensing will be studied in detail. The specific contents are as follows: Firstly, the controlled synthesis of different size, morphology and functionized inorganic nano-sized semiconductor, heterojunction semiconductor and nano-sized Au. Secondly, the effects of the size, morphology, spacing and ambient medium of nano-sized Au and the distance between it and photoelectric beacon on photocurrent will be further researched. Thirdly, the aptamer or catalyzing enzyme will be highly assembled on the surface of nano-sized Au and the mechanism between the probes and targets will also be discussed. In a word, a new mechanism or system of the high performance nano-sized Au enhanced photoelectrochemical sensing will be developed and it can be applied to the ultrasensitive, label-free and fast determination. This work will creatively integrate the merits of nano-sized Au localized surface plasmon resonance and the photoelectrochemical sensing, which expands the application fields of nano-sized Au and provides a novel platform for the determination and establishment of the early-warning mechanism for food safety. In addition, it will also promote the development of the photoelectrochemical sensing.

纳米贵金属等离子体能够有效集聚能量，提高光激子浓度并促进半导体载流子分离，现已成为光伏领域的研究热点。针对光电化学传感体系载流子易复合、灵敏度不高等问题，本项目将开展纳米金局域表面等离子体共振在光电化学传感领域的系统性研究，揭示其增强光电化学传感的作用机制。研究不同尺寸、形貌功能无机纳米半导体或其异质结半导体和纳米金的可控合成；深入探究纳米金与光电信标的组装间距和纳米金的尺寸、形貌、间距以及周围介质对光电信号的影响；调控核酸适配体或催化酶在纳米金上的高密度组装；探讨探针与靶分子的作用机制；建立高效纳米金局域表面等离子体共振增强光电化学传感的新原理与新体系，以实现超灵敏、免标记及快速检测。本工作创造性地集成纳米金局域表面等离子体共振和光电化学传感的优点，拓展了纳米金的应用领域，为食品安全检测及预警机制的建立提供新平台，并将促进光电化学分析领域的发展。

光电化学传感是基于识别元件结合靶标前后引起光电流的变化来确定待测组分含量的一种新型分析方法。由于目前报道的光电化学传感体系存在载流子对易复合、灵敏度不高等问题。因此，寻求有效方案提高光电化学检测灵敏度是分析工作者的重要课题。最近引人注目的纳米金局域表面等离子体共振（Localized Surface Plasmon Resonance, LSPR）效应在纳米光子学、生物光子学、太阳能电池和癌症的诊断和治疗等领域被广泛关注，其局域表面等离子体聚焦能量能够提高半导体载流子对的浓度并促进其快速分离，因此其可以增强光电化学传感信号。把物理光学现象中的LSPR耦合至光电化学分析领域将成为光电化学分析学科前沿发展的新生长点。我们主要完成了如下的研究工作：基于纳米贵金属等离子体能够有效集聚能量，提高光激子浓度并促进半导体载流子分离，进而可以提高光电检测信号的原理，我们开展了纳米金局域表面等离子体共振在光电化学传感领域的系统性研究，揭示了其增强光电化学传感的作用机制。研究了不同尺寸、形貌功能无机纳米半导体或其异质结半导体和纳米金的可控合成；深入探究了纳米金与光电信标的组装间距和纳米金的尺寸、形貌、间距以及周围介质对光电信号的影响；通过调控核酸适配体或催化酶在纳米金上的高密度组装，探讨了探针与靶分子的作用机制；建立了高效纳米金局域表面等离子体共振增强光电化学传感的新原理与新体系，实现了超灵敏、免标记及快速检测。集成了纳米金局域表面等离子体共振和光电化学传感的双重优点，拓展了纳米金的应用领域，为食品安全检测及预警机制建立了新平台，并将促进光电化学分析领域的发展。