基于上转换荧光纳米材料的超灵敏生物传感新方法研究

Upconversion nanoparticles (UCNPs) are a novel class of nanophosphors that can be excited in near infrared region to give emission in visible region. In comparison to traditional organic dyes and semiconductor quantum dots, UCPNs show superior chemical and optical properties, including low toxicity, large Stokes shift, long fluorescence lifetimes, high photostability, low background fluorescence and scattered light and deep penetrating light scales. These properties make UCNPs an ideal fluorescent probes for bioassay, cell imaging and biomedical research. This project aims to synthesis of water-dispersible UCNPs as the energy donor. A series of simple, rapid, ultrasensitive and universal biosensing strategies will be developed for protein detection and tumour cell imaging analysis by fluorescence resonance energy transfer between UCNPs and fluorescence acceptor, combined with DNA terminal protection assay, rolling circle amplification, nicking endonuclease-assisted target recycling amplification and hybridization chain reaction amplification. Moreover, these universal technologies can be easily extended to the determination of other biomolecules such as DNA and RNA. Therefore, it would provide a simple and practical technological platform for cancer early diagnosis, clinical treatment and drug screening.

上转换荧光纳米材料（UCNPs）是在近红外区激发、可见光区发射的一种新型荧光材料。与传统的有机染料和半导体量子点相比，UCNPs具有许多优越的性能，如毒性低、Stokes位移大、荧光寿命长、光学性能稳定、较低的背景荧光和杂散射光、较深的光穿透尺度等，因此可作为理想的荧光标记物应用于生化分析、细胞成像和生物医学等领域。本项目拟合成单分散性好的上转换纳米颗粒，并以此作为能量供体，结合核酸末端保护分析技术、滚环扩增技术、核酸切刻酶辅助目标循环放大技术和杂交链反应放大技术，探索发展简单、快速、超灵敏的荧光能量转移生物传感新技术，实现对蛋白质的灵敏检测，并期望应用于肿瘤细胞的成像分析。同时，该方法的通用性较好，能够拓宽到其它生物分子的检测，有望为癌症早期诊断、临床治疗和药物筛选等领域提供一个简便实用的新技术平台。

项目合成毒性低、光学性能稳定、生物相容性好的荧光纳米材料，并作为信号探针，针对小分子与其结合蛋白质相互作用这一问题，以小分子连接核酸末端保护分析为基础，系统开展核酸末端保护分析生物传感技术研究；以核酸外切酶识别为基础，发展T7核酸外切酶辅助目标循环放大方法；以聚合酶和核酸外切酶生物识别为基础，探索建立滚环扩增信号扩大集联核酸外切酶III辅助目标循环放大技术；在此基础上，构建了一系列快速、高选择性、超灵敏的蛋白质检测的荧光生物传感新方法，为癌症、遗传病等重大疾病相关机理与分子诊断研究构建简便实用的新技术平台。目前项目已完成了计划内容，在Biosensors and Bioelectronics、Sensors and Actuators B: Chemical等国际SCI期刊上发表论文十五篇，申请国家发明专利3项。