基于近红外量子点复合物的高灵敏度真菌毒素生物传感器

This project proposes a novel strategy of signal and selective enhancing of multi-component nanocomposites to design a new type of mycotoxins near-infrared biosensors with high selectivity and sensitivity, consisting of no fluorescence emission of biotoxins and endogenous substances in near-infrared emission. Controllable self-assembly of multi-component near-infrared fluorescence quantum dots/aptamer nanocomposites is on the basis of 5.0 G poly amidoamine (PAMAM), linking agent and modifier, with good biological compatibility and load for many particles simultaneously, and raw materials such as III-V quantum dots and their blends, graphenen, aptamer (or antigen/antibody). This project studies multi- component bio-nanocomposites from various perspectives: studying the influence of the factors on their controlled self-assembly and their law of controlling; charactering their morphology, structure, and properties with TEM, XRD, electro- chemical method and spectroscopic methods; revealing the relationship among their morphology, composition, and properties; establishing a controllable self- assembled method of a new type and high efficient near-infrared fluorescence quantum dots/graphenen/PAMAM/aptamer (antigen/ antibody) multi-component bio-nano- composites. The multi-component near-infrared fluorescence quantum dots/ aptamer nanocomposites show very promising applications in the fabrication of biosensors for high sensitive and selective detection of mycotoxins(such as aflatoxins, ochratoxin et.al), the application of the signal enhancement of the multi-component nanocomposites together with the high selectivity of aptamer or antigen/antibody. This project can be helpful to detect mycotoxins (such as aflatoxins, ochratoxin et.al) in food. This project therefore can produce a new type of multi-component near-infrared nanocomposites biosensor- material, and provide a new way to develop high selective and sensitive near-infrared biosensors.

本项目拟利用生物毒素和内源性物质在近红外区无背景荧光的特性，设计一种高选择性、高灵敏新型近红外量子点适配体真菌毒素生物传感研究平台；以生物兼容性好和同时负载多种粒子的5.0 G PAMAM为交联剂与修饰剂，以III-V系及其混合型近红外量子点、石墨烯、适配体等为基础物质，进行多组分纳米复合物可控自组装。研究影响多组分纳米复合物自组装的因素和调控规律；应用TEM、XRD和谱学技术等表征多组分纳米复合物的形貌、结构与性能；研究多组分纳米复合物结构、形貌与性能的关系，建立高效近红外量子点-石墨烯-PAMAM-适配体复合物的可控自组装方法。研究真菌毒素传感器的响应机理和信号放大机制；纳米复合物增强信号与适配体高识别性相结合，建立真菌毒素高选择性、高灵敏近红外荧光传感分析新方法。该课题可望展一类新型多组分近红外量子点荧光纳米复合物生物传感器，为快速、简单、高灵敏检测食品中生物毒素提供了新思路。

研究了碳量子点的形成机理，建立了近红外碳量子点可控制备方法，制备系列近红外荧光碳量子点；建立了碲化镉量子点的绿色合成方法，合成了系列近红外荧光碲化镉量子点。研究了自组装条件、自组装方式和复合物组成对复合物性能的影响和调控规律，制备了系列适配体（Apt）量子点复合物并进行了形貌表征和性能研究；筛选出了系列性能优异的纳米复合物；构建了高选择性、高灵敏真菌毒素传感研究平台。分别以银纳米簇、铜纳米簇和近红外碳量子点为探针，建立了高选择性、高灵敏检测黄曲霉毒素B1、T-2毒素和赭曲霉毒素A的近红外传感检测体系；研究了纳米复合物传感信号响应与放大机理，研究了两种真菌毒素同时检测的信号干扰消除问题，建立了以金纳米粒子、适配体和量子点组成的五组分量子点复合物为探针同时检测黄曲霉毒素B1和赭曲霉毒素A的近红外传感检测体系，检测限分别为3pg/mL和9pg/mL。设计了磁分离方法和电化学法消除背景干扰的方法，改善传感器的检测灵敏性，建立了高选择性、高灵敏赭曲霉毒素A荧光传感检测体系和脱氧雪腐镰刀菌烯醇电化学传感检测体系，对赭曲霉毒素A和脱氧雪腐镰刀菌烯醇的检测限分别为0.3pg/mL和3pg/mL。发现了三乙基四胺六乙酸(TTHA)光催化剂，研究了催化机理，建立了基于Au@Fe3O4/Atp-DNA-TTHA复合物的高灵敏光催化黄曲霉毒素B1传感检测体系，检测限为650fg/mL。这些方法初步应用于食品药品中痕量真菌毒素检测，结果显示能满足实际要求。项目研究为食品药品中真菌毒素检测提供了一类高选择性、高灵敏、简单、快速的新方法。