双光子比例型荧光纳米探针的构建及生物成像应用研究

Biomolecules, metal ions and anions play important roles in physiological processes. the development of methods to detect and image them in biological samples such as living cells and tissues, is of considerable importance and has become a current focus of chemical research. The fluorescent probe method seems to be an ideal candidate for both sensing and bioimaging analytes in various samples. two-photon microscopy (TPM) offers several advantages, including minimum photodamage and background autofluorescence interference, higher spacial resolution, and longer observation time for imaging deep inside a tissue. However, nearly all TP probes are based on single emission intensity changes, which tend to be affected by a variety of factors such as instrumental efficiency and environmental conditions. And double emission intensity changes ratiometric probes are rarely seen. In this project, thanks to the load capacity and high biocompatibility of the mesoporous silica nanoparticles (MSNP), we innovatively attempt to construct a two-photon ratiometric sensing platform by bonding two types of two-photon dyes to MSNP through a click reaction. Due to the advantages of two-photon microscopy, ratiometric sensing and high biocompatibility of MSNP, this design strategy can achieve the in situ, real-time monitoring of intracellular biological molecules, metal ions and anions with high sensitivity and accuracy, which will provide a valuable theoretical basis and technical support for the early diagnosis of the disease.

生物小分子、金属离子及阴离子在生理过程中扮演着极其重要的角色，获取它们在生命体内的分布信息具有重要的生物医学意义，荧光探针结合荧光成像技术正是获取这些信息的有效手段。双光子成像技术由于其对样品损伤小、避免自发荧光干扰、分辨率高、可长时间对深层组织进行成像观测而尤为引人注目。然而，绝大多数已报道的双光子探针均是基于单荧光发射峰构建，易受到仪器误差、人工误差等影响而产生假阳性结果，而双发射峰的比例型探针又极为少见。本项目针对这一现状，结合介孔硅纳米材料的负载能力和生物相容性，创新地将两类双光子染料通过点击化学键联到介孔硅上构建双光子比例型荧光检测平台。实现对生理环境中被分析物高灵敏度和高准确性的成像研究，更为准确地获取这些生物分子或离子在生命体内的分布信息，为疾病的早期诊断提供有价值的理论依据和技术支持。

生物小分子、金属离子及阴离子在生理过程中扮演着极其重要的角色，获取它们在生命体内的分布信息具有重要的生物医学意义。得益于响应快速、灵敏高、选择性好、可原位实时检测等优点，基于小分子荧光染料和探针的荧光成像技术已成为获取这些信息的有效手段。目前具有优越光物理性质和成像功能的染料及探针开发一直是研究难点和热门。针对目前荧光探针大都是短波长激发和荧光发射，样本易受光损伤、背景荧光干扰严重以及穿透深度不够等缺陷，本项目以开发新型远红-近红外区荧光染料HN1-7为核心，并以该染料合成了构建了一系列功能化荧光探针用于溶酶体靶向检测pH值、次氯酸和硒代半胱氨酸。所构建的探针体系在体外分析性能测试和体内荧光成像上获得了良好的效果，可获得较大的成像深度以及避免背景荧光干扰，在细胞、组织和小鼠成像中具有一定的优势。本项目的研究成果可为生理与病理进程的研究以及疾病的早期诊断提供有价值的理论依据和技术支持。