稀土掺杂荧光温度传感材料设计与合成

发布时间：2018-01-08 21:11

本文关键词：稀土掺杂荧光温度传感材料设计与合成　出处：《浙江大学》2015年硕士论文　论文类型：学位论文

【摘要】：稀土掺杂荧光温度传感纳米材料,是一类通过稀土离子的特征荧光来探测温度的功能材料。因其对温度的探测快捷、信号准确,材料尺寸小而被广泛应用,特别是在生物及医药领域。对于生物体,温度的高低体现其生命活动的强弱,微观上是细胞新陈代谢强弱的体现,如处于分裂的细胞温度高于稳定细胞,癌细胞温度高于正常体细胞。因此,研究生物体内微观区域温度的分布及变化有着重要的意义,有助于研究细胞生命活动以及对疾病的研究、预防、诊断和治疗。然而,目前荧光温感材料的研究存在材料尺寸大、有毒不稳定、探测不准确、非自矫正性、信号差异小、灵敏度低、紫外激发、激发和发生光不处于生物窗口以及生物制热效应等诸多缺点。因此为了避免上述缺点,本文通过三个创新性系列研究,逐步深入,获得了较理想的生物用稀土掺杂荧光温度传感材料。研究内容、结果及创新性分述如下：一、单光谱荧光强度型温度传感研究：激发和发射光谱均处于生物窗口目前单光谱荧光强度型温度传感存在材料毒性、需紫外或者蓝光激发、发射谱不处于生物窗口等缺陷。因此,我们成功设计了Yb3+-Er3+离子共掺杂KMnF3纳米材料体系,利用Yb3+离子吸收生物窗口980 nm激光以及Yb3+-Er3+组合有效的上转换的特性,同时借助Mn2+离子1T4独特能级有效吸收Er+离子4F9/2(～660nm)能级以上能量(2H9/2,483/2)并将能量回传给4F9/2,获得了具有同生物窗口980nm激发660 nm单谱发射,粒径～14.9 nm的KMnF3无毒纳米材料；并在40～100℃展示出6.2～6.7%K-1高于同类研究的灵敏度。本研究的创新点在于巧妙借助了Mn2+离子与Er3+离子之间的能量作用使得Er3+离子只发射出660 nm单谱荧光,实现同生物窗口激发和发射的单光谱温度传感。然而,其缺点是发光易受非温度因素影响、不具有自矫正性。二、双光谱荧光温度传感研究：实现自矫正性能及激发光位于生物窗口由于单光谱不具有自矫正、不能实现精准温度测量；其他双光谱研究存在信号差异细微,灵敏度低,材料尺寸较大,需紫外激发等不足。因此,我们首次提出利用稀土掺杂核壳纳米结构实现具有自矫正、信号差异大、灵敏度高、具有近红外光激发性能的双光谱温度传感研究。利用热分解沉淀法获得了～25 nm的NaGdF4:Tm3+/Yb3+@NaGdF4:Tb3+/Eu3+核壳纳米颗粒。在980 nm的激发下,监测Tb3+(～545nm)与Eu3+(～615nm)的荧光强度比随温度的变化获得了125～300 K温度区间1.2%K-1高的温度灵敏度。本研究的创新点在于首次利用稀土掺杂核壳纳米结构来实现双光谱温度传感的研究,是一种新的研究思路。通过核壳结构,改变了离子空间的分布以及调控了稀土离子的能量传递方式,最终实现了近红外激发下,基于双谱探测的高灵敏度自矫正温度传感研究。该研究的不足在于发射光谱不处于生物窗口。三、较理想双光谱荧光温度传感研究：激发和发射光谱均处于生物窗口且无生物制热效应双光谱弥补了单光谱不具有自矫正的缺陷,然而目前众多双光谱温度传感研究其激发和发射光谱不处于生物窗口,同时具有严重的生物制热效应(980 nm导致)。因此,本研究借助核壳结构设计思想,设计合成了粒径为42～49nm的NaYF4:Tm3+/Yb3+@NaYF4:Yb3+/Nd3+核壳纳米颗粒。在808 nm的激发下,监测Tm3+离子～696 nm与645 nm荧光强度比随温度的变化,实现了40～240℃温度区域高灵敏度(最高1.54%K-1)的温度探测。本研究的创新点在于利用Nd3+离子作为敏化剂离子,实现了无生物热效应的808 nm激发,从而首次实现激发和发射光谱均处于生物窗口而又无制热效应的高灵敏度双光谱荧光温度传感研究。
[Abstract]:Rare earth doped fluorescence temperature sensing nano materials are functional materials to detect the temperature of a class by rare earth ions. Because of its characteristic fluorescence temperature quick detection, accurate signal, small size materials have been widely used, especially in biological and medical fields. For the temperature of the organism, reflect the life strength micro is a manifestation of the strength of the cell division in The new supersedes the old., such as the cell temperature is higher than that of stable cells, cancer cell temperature is higher than that of normal cells. Therefore, plays an important role in the change and distribution of micro organisms in regional temperature, contribute to the study of cell life activities and research, disease prevention, diagnosis and treatment. However, the current study materials are temperature sensitive fluorescent material with large size, toxic instability, detection is not accurate, non self correction, the signal difference is small, low sensitivity, UV excitation, and excitation Light is not the biological window and biological heating effect and many other shortcomings. So in order to avoid the above shortcomings, this paper through the three series of innovative research, step by step, obtained an ideal biological use of rare earth doped fluorescence temperature sensing materials. The research contents, results and innovative points are as follows: first, a single spectrum research on temperature sensing type: the fluorescence intensity of excitation and emission spectra are in the current window biological fluorescence intensity of single type temperature sensing materials are toxic, UV or blue light excitation, emission spectrum is not in the biological window and other defects. Therefore, we successfully designed a Yb3+-Er3+ ion Co doped KMnF3 nano material system, using Yb3+ ion absorption biological window 980 nm laser and Yb3+-Er3+ combination effective conversion characteristics, at the same time with the Mn2+ ion 1T4 unique level effective absorption of Er+ ions 4F9/2 (~ 660nm) above the level of energy (2H9/2483/2) and the energy back to the 4F9/2, obtained has the same biological window 980nm 660 nm single excitation emission spectra, particle size of ~ 14.9 nm KMnF3 non-toxic nano materials; and in the 40 to 100 DEG C shows 6.2 ~ 6.7%K-1 higher than similar sensitivity research. The innovation of this research is the interaction between the clever use of energy Mn2+ ion and Er3+ ion makes Er3+ ions emit only a single 660 nm fluorescence spectrum, to achieve the same biological window excitation and emission spectra of the single temperature sensor. However, its shortcoming is easily affected by non luminous temperature factor, does not have a self correction. Two, double optical spectra of fluorescence temperature sensing: self correction the performance and the excitation light in biological window due to the single spectrum with self correction, can achieve precise temperature measurement; the other two spectra signal the existence of subtle differences, low sensitivity, large size materials, UV excitation due to insufficient. For this, we first proposed the use of rare earth doped core-shell structure with self correction, the signal difference is big, high sensitivity, double spectral temperature sensing with near-infrared excitation properties. Precipitation was 25 ~ NaGdF4:Tm3+/Yb3+@NaGdF4:Tb3+/Eu3+ core-shell nanoparticles by thermal decomposition of nm. Under 980 nm excitation, the monitoring of Tb3+ (~ 545nm) and Eu3+ (~ 615nm) the fluorescence intensity obtained the temperature sensitivity of 125 K to 300 1.2%K-1 higher than the temperature range varies with temperature. The innovation of this research is the first use of rare earth doped core-shell structure to achieve the double spectrum research of temperature sensing, is a new research method. Through the nuclear shell the structure, spatial distribution and changes the ion regulation of rare earth ion energy transfer mode, finally realizes the near infrared excitation, bispectrum detection with high sensitivity of the temperature sensor based on self correction research The limitations of this research. In emission spectrum is not biological window. Three, the ideal temperature sensor based on double fluorescence excitation and emission spectra are: biological and non biological heating effect of window double spectrum for single spectrum is not self correcting defects, but the current number of double spectrum temperature sensor based on the excitation and the emission spectra in biological window, with biological serious thermal effects (980 nm lead). Therefore, this study design with core-shell structure, particle size of 42 ~ 49nm NaYF4:Tm3+/Yb3+@NaYF4:Yb3+/Nd3+ core-shell nanoparticles were synthesized. Under 808 nm excitation, Tm3+ ion monitoring to 696 nm and 645 nm the fluorescence intensity ratio changes with the temperature, the temperature of 40~240 DEG C high sensitivity (up to 1.54%K-1) temperature detection. The innovation of this research is to use Nd3+ ions as sensitizer ion, implementation The 808 nm excitation with no biological heating effect is achieved. For the first time, a high sensitivity dual spectrum fluorescence temperature sensing with both excitation and emission spectrum in biological window and without heating effect is first realized.

【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB34

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