【作者】 杨豪；

【导师】 杨海朋；

【作者基本信息】 深圳大学 ， 材料工程（专业学位）， 2020， 硕士

【摘要】 稀土上转换荧光纳米材料是一种将长波长近红外激发光转换为短波长可见光的一种新型荧光材料。其特性使得其在激光器件、太阳能电池、光热治疗、生物化学传感等领域引发了科研工作者的广泛关注。稀土上转换荧光纳米材料在激光辐照下有更深的组织穿透能力、高化学稳定性、低毒性以及优良的信噪比,这使得该材料在生物荧光成像,荧光化学生物传感器以及光动力治疗领域具备优势。本文依据荧光共振能量转移现象,通过构建荧光传感器来实现对香豆素,三聚氰胺以及葡萄糖的含量传感。本论文的主要创新点和研究内容如下:（1）通过水热法制备出六方相以及四方相的NaYF₄:Yb;Er纳米粒子。利用制备得到的NaYF₄:Yb;Er纳米粒子,构建出一个基于荧光共振能量转移体系的香豆素荧光传感器。在该体系中,应用了主客体识别作用作为分子识别方式,将修饰了环糊精的NaYF₄:Yb;Er纳米粒子作为能量供体,罗丹明6G作为荧光受体,利用罗丹明6G和香豆素对环糊精的竞争结合实现香豆素的浓度检测。（2）三聚氰胺作为一种对人体有害的物质,开发一种简便的浓度检测方法具有一定的意义。通过溶剂热法来制备核壳型上转换纳米粒子NaYF₄:Yb;Er@NaYF₄。去除油酸配体的NaYF₄:Yb;Er@NaYF₄作为荧光供体,三聚氰胺结合的AuNPs作为荧光受体,基于两者之间的荧光能量转移过程,构建三聚氰胺的荧光传感方法。AuNPs和三聚氰胺结合后,AuNPs的吸收峰强度下降,加入上转换纳米粒子溶液中,荧光共振能量转移的效率降低,从而构建三聚氰胺的荧光化学传感体系。（3）基于荧光共振能量转移体系,选择激发波长为808 nm的上转换荧光纳米材料NaYF₄:Yb;Er;Nd@NaYF₄作为荧光材料。将修饰了去活化中心葡萄糖氧化酶的上转换纳米粒子作为能量供体,葡聚糖改性的AuNPs颗粒作为能量受体,构建选择性强、简单方便的葡萄糖荧光生物传感器。通过荧光强度的变化,实现对葡萄糖含量的特异性检测。更多还原

【Abstract】 Rare earth up-conversion fluorescent nanomaterial is a new type of fluorescent material that converts long-wavelength near-infrared excitation light into short-wavelength visible light.Due to its unique properties,it has attracted widespread attention of researchers in laser devices,solar cells,photothermal therapy,biochemical sensing,and other fields.Rare earth upconversion fluorescent nanomaterials have advantages in fluorescence imaging,fluorescent chemical biosensors,and photodynamic therapy due to their deeper tissue penetration,high chemical stability,low toxicity,and excellent signal-to-noise ratio.Based on the phenomenon of fluorescence resonance energy transfer,the concentration analysis of coumarin,melamine,and glucose was realized by constructing a fluorescence sensor.The main innovations and research contents of this paper are as follows:（1）Hexagonal and tetragonal NaYF₄:Yb;Er nanoparticles were prepared by the hydrothermal method.With the prepared NaYF₄:Yb;Er nanoparticles,a coumarin fluorescence sensor based on a fluorescence resonance energy transfer system was constructed.In this system,host-guest recognition is used as molecular recognition method,NaYF₄:Yb;Er modified with cyclodextrin are used as energy donors,and rhodamine 6G is used as a fluorescent acceptor.The competitive combination of cyclodextrin enables the detection of coumarin concentration.（2）As a substance harmful to the human body,it is of great significance to develop a simple method to detect melamine concentration.Core-shell type up-conversion nanoparticles NaYF₄:Yb;Er@NaYF₄ were solvothermal used.The Ligand-free nanoparticles are used as fluorescent donors,and the melamine-bound AuNPs are used as a fluorescent acceptor,which facilitates the process of fluorescence energy transfer between the two and constructs a melamine fluorescent chemical sensor.After mixing melamine and AuNPs,the intensity of the absorption peak of AuNPs decreases,and the efficiency of fluorescence resonance energy transfer decreases with the addition of up-converted nanoparticles,thereby constructing a melamine fluorescent chemical sensing system.（3）Based on the fluorescence resonance energy transfer system,808 nm excited groundconverted fluorescent nanomaterials NaYF₄:Yb;Er;Nd@NaYF₄ were selected as fluorescent substances.An up-converted nanoparticle modified with glucose oxygenase was used as an energy donor,and dextran-modified AuNPs particles were used as energy acceptors.A fluorescent biosensor with good selectivity,simplicity,and convenience was constructed.The specific detection of glucose content was realized by the change of fluorescence intensity of the system.更多还原