基于双功能金簇的新型双光子比率型荧光探针的构建及生物成像应用研究

Two-photon microscopy (TPM) has the advantages of high penetration depth, high spatial resolution and low phototoxicity, combining TPM with ratiometric fluorescent probes can realize biosensing and bioimaging of disease-related intracellular biological molecules and metal ions.However, most of two-photon ratiometric fluorescent probes are designed based on small molecules, which has such shortcomings as high design requirements, poor water solubility, and short retention time in vivo. Taking advantage of the two-photon fluorescence and quenching properties of dual functional gold nanoclusters (AuNCs) and strong membrane penetrating ability of two-photon silicon nanoparticles (SiNPs), this project intend to develop a dual - emission-probe strategy. Based on this strategy, we plan to develope a series of two-photon ratiometric fluorescent probes with large tissue penetrating depth, long cycle time, high imaging resolution, good biocompatibility, high sensitivity and selectivity for bioimaging of biological molecules and metal ions (such as Cyt-c, ATP, Pb2+) in cells and tissues. This project is expected to get information of the dynamic distribution of target analytes in vivo, which will provide potentially useful tools and technical support for early diagnosis of disease and pathobiology investigation.

双光子荧光成像技术具有样本穿透深度大、空间分辨率高以及光毒性小等优点，将其与比率型荧光探针相结合，可实现对生物样品中疾病相关分子与金属离子的生物分析及成像。然而，目前的双光子比率型荧光探针大多是基于小分子设计，在合成及应用上存在设计要求高、水溶性差、体内保留时间短等问题。本项目拟将兼具双光子荧光性质和猝灭性质的新型双功能金纳米簇与膜穿透能力强的双光子硅纳米颗粒相结合，提出具有组织穿透度深、体内保留时间长、成像分辨率高等优点的单激发双发射荧光探针策略。基于该策略，我们拟构建一系列灵敏度高、选择性好、设计简单、生物相容性好的新型双光子比率型荧光探针，实现对细胞或组织细胞色素C、ATP、Pb2+等疾病相关生物分子与金属离子的灵敏检测及双光子成像。本项目的完成有望获取目标分子在生物体内的动态分布信息，为疾病的早期诊断及相关病理的研究提供有效的分析手段和技术支持。

近红外光激发的荧光成像技术（双光子/上转换发光）具有样本穿透深度大、空间分辨率高以及光毒性小等优点，将其与比率型荧光探针相结合，可实现对生物样品中疾病相关分子与金属离子的生物分析及成像。然而，目前的双光子比率型荧光探针大多是基于小分子设计，在合成及应用上存在设计要求高、水溶性差、体内保留时间短等问题。基于此，本项目合成了具有近红外发光的双光子染料/纳米材料及上转换纳米材料，并基于这些发光团构建了一系列灵敏度高、选择性好、设计简单、生物相容性好的近红外光激发的比率型荧光探针，实现对细胞内硝基还原酶，HClO，miRNA，Pb2+等疾病相关生物分子与金属离子的灵敏检测及成像，为疾病的早期诊断及相关病理的研究提供有效的分析手段和技术支持。项目支助发表SCI论文8篇，待发表三篇，培养研究生2名。