高生物相容性NaXF4:Ln@NaXF4@C纳米晶的可控制备及发光性能研究

Due to the weak background autofluorescence, deep tissue penetration of excitation light and high stability, rare earth up-conversion luminescent materials have a wide application prospect in the field of biological imaging. The samples prepared by the commonly used synthetic methods are mostly only dispersed in oil phase, therefore surface modification is needed for biological fluorescence labeling. In this project, two ways of in-situ carbon coating and nano-carbon composite coating will be used to modify the surface of core-shell rare earth up-conversion nanocrystals. The luminescent properties of carbon coated samples were studied, and their biocompatibility was evaluated. By optimizing the carbon coating conditions, the location, thickness and carbon structure of the core shell structure up-conversion nanocrystals with different morphologies were analyzed, and the key influencing factors of carbon coating on the luminescence properties of nanocrystals were elucidated. The binding energy of carbon and different crystal surfaces will be calculated by modeling calculation, exploring the capture and transfer mechanism of near infrared light in carbon coated rare earth up-conversion nanocrystals combining carbon distribution. The implementation of the project is expected to develop carbon coating into high a high universal method for rare earth nanocrystals surface modification, giving them high biocompatibility and high luminescence efficiency, and provide experimental basis for further functionalization.

稀土上转换发光材料因自发荧光背景小、激发光对组织穿透深、稳定性高而在生物成像领域具有广泛的应用前景。常用的合成方法制备的样品多数只能分散在油相中，用于生物荧光标记需要进行表面改性。本课题采用原位碳包覆和纳米碳复合包覆两种方式对不同形貌核壳结构稀土上转换纳米晶进行表面改性，研究碳包覆样品的发光性能并进行生物相容性评价。通过优化碳包覆条件，分析不同形貌核壳结构上转换纳米晶的碳包覆位置、厚度和碳结构，阐明碳包覆对纳米晶发光性能的关键影响因素。对碳与不同晶面的结合能进行建模计算，揭示碳分布位置规律、探索近红外光在碳包覆稀土上转换纳米晶中的捕获和传递机制。项目的实施有望将碳包覆发展成为高普适性稀土上转换纳米晶表面改性新方法，使其具有高生物相容性和较高的发光效率，并为进一步功能化提供实验依据。

稀土上转换纳米材料因自发荧光干扰少、激发光对组织穿透深、稳定性高而在生物成像和肿瘤治疗领域受到广泛关注，用于生物成像或治疗领域时多采用表面改性的方法提高其生物相容性。本课题采用纳米氮化碳复合的方式对稀土上转换纳米晶进行改性，研究了近红外光下稀土上转换纳米晶的荧光性质、微观结构以及复合材料的光热转换性质，并对材料的生物相容性进行了评价，对其抗肿瘤效果进行了体外体内实验评价。在此基础上，设计了MOF衍生等方式获得纳米碳复合材料，研究了其对于近红外激光的响应能力、光热转换性质及尺寸、形貌等微观性质，并对其生物相容性、体内体外抗肿瘤作用进行了评价。项目的实施开发了具有高生物相容性的纳米碳/稀土上转换纳米晶复合材料，获得了体外体内抗肿瘤效果评价数据，为更多高生物相容性纳米材料的开发提供了借鉴。