1. 研究目的与意义（文献综述）

进入新的世纪后，人类在生物领域的研究转向了分子水平，对生物分子进行标记并想办法让研究者能观测其在生物体内的的行为成了当代生物研究中很重要的课题，而荧光显微术便是为此诞生的一种手段，荧光显微术使用荧光染料对蛋白质分子进行标记后成像从而达到对目标蛋白进行追踪的目的，然而传统的生物荧光染料的使用过程中有几大困难，首先蛋白质分子本身会辐射荧光，很不巧有时染料辐射的荧光波长与生物自身蛋白质辐射的荧光波长相近，这为成像带来了巨大的困难，其二，传统的染料荧光持续时间不够令人满意，这使得很多持续几小时至几天的实验的开展有很大的困难。正当生物学家为此烦恼时，量子点材料为其带来了希望，量子点材料由于吸收辐射的机制与传统染料不同，其通过调整能带的结构可以控制辐射光的波长，且由于量子点存在二次激发效应，发光时间也很长，可以持续数小时，甚至几天，这些优点使得量子点经过功能化改造后有潜力成为极好的生物成像材料。量子点在应用之前需要进行改造，如包一层外壳，来减少表面缺陷从而提高发光效率以及避免量子点材料本身发生氧化反应等反应，之后，还要用基团对量子点表面修饰来增加材料水溶性和对量子点功能化，功能化主要是在量子点表面组装能与目标蛋白质分子结合的分子片段，从而让量子点能够特异性标记靶分子。经实验证明，量子点材料对生物体的毒性极低，在安全范围内对生物几乎没有负面影响，但在极高浓度下会影响胚胎的发育，量子点的完全无毒化是一项挑战，也是其能用于临床的一大必需的条件。本实验旨在合成一种可以发射近红外ii区段荧光的量子点材料，近红外光易于与生物蛋白质的自身辐射荧光区分，因而其成像能力优秀，有很好的前景。为了能得到近红外量子点，需要对它的能带结构进行调整，而这可以通过调整量子点的核式结构的尺寸来完成。在合成过程中对合成条件加以控制，如温度，反应时间，以及添加剂等，便可以控制量子点材料的粒径，最终获得辐射目标波段光子的量子点材料。本工作为将为开发应用于生物成像的近红外荧光探针奠定基础，极有希望应用于疾病诊断和精准医学领域。

in the new century, biologists start to focus onstudies of molecular biology. to label molecules in live cells and observe howthey work is very important, for which the fluorescence microscopy is born. thestandard dye used in fluorescence microscopy labels proteins and make them ableto be observed and be tracked. however, standard dyes have two big problem thatneed to be solved-cell autofluorescence in thevisible spectrum and the requirement of long observation times. qdotsdistinguish themselves from commonly used fluorophores by some characteristics.qdots have special mechanisms of absorption and emission so qdots can emitphoton of required wavelength by changing the construction of energy band andhave a long lifetime can maintain hours to couple of days because of theradiative recombination. qdots need to be engineered before it canbe applied, for instance, coated by a shell to decrease detects and avoid beingoxidized or combined with some groups to make qdots soluble and functionalized.functionalization means adding some molecules, for instance, peptide, anti-bodybiotin etc, which can combine with protein specifically to the surface of qdotsthen the qdots have the ability to label target protein that needs tracked.according to published reports, below a safety concentration, adverse effectson cell viability, morphology, function or development over the duration of theexperiments (from several hours to several days) are not found. however,negative effects on embryo development can be noticed at high concentration ofqdots due to emission of some kinds of ions toxic to cell . extensive scrutinyis a great challenge, meanwhile it is also a subject needs much efforts beforeit can be used in human body. the experiment aims to synthesize a kind of qdotswhich can emit photon in the nir-ii window. photon in the nir-ii window can beeasily separated from cell autofluorescence, for which the nir-ii qdots have agood capacity of imaging. in order to get such qdots, the energy band needs tobe constructed which can be achieved by changing the size of qdots. during thesynthesis, the change of reaction conditions can control the radius of qdotsparticles then the energy band construction can be controlled. such reactionconditions include temperature, time of the duration of reaction and additivesetc. this work will benefit the study of nir fluorescent probe and have a greatpossibility to be applied to disease diagnosis and accurate medical science.

2. 研究的基本内容与方案

2.1 基本内容

1．文献调研，了解国内外相关研究概况和发展趋势，了解选题与社会、健康、安全、成本以及环境等因素的关系；

3. 研究计划与安排

第1－3周：查阅相关文献资料，完成英文翻译。明确研究内容，了解研究所需原料、仪器和设备，并明确论文所用原材料和测试及分析费用。确定技术方案，并完成开题报告。

第4－9周：按照实验方案，完成近红外荧光量子点材料的合成。

4. 参考文献（12篇以上）

1. michalet,x.; pinaud, f. f.; bentolila, l. a.; tsay, j. m.; doose, s.; li, j. j.;sundaresan, g.; wu, a. m.; gambhir, s. s.; weiss, s., quantum dots for livecells, in vivo imaging, and diagnostics. science 2005, 307, 538-544.

2. zhang, m.;yue, j.; cui, r.; ma, z.; wan, h.; wang, f.; zhu, s.; zhou, y.; kuang, y.;zhong, y.; pang, d.-w.; dai, h., bright quantum dots emitting at ～1,600 nm in the nir-iib window for deep tissuefluorescence imaging. proc. natl. acad. sci. usa 2018, 115, 6590-6595.