核盘菌引起的油菜菌核病是造成油菜籽减产的重要原因之一，对植株核盘菌感染致病机理研究利于针对性防控技术研发。细胞内酸碱度变化是植株对发育状态的反馈，细胞pH的检测对致病机理研究具有重要意义。近年来，近红外光激发的稀土上转换发光材料在生物检测方面得到了广泛的应用，但其发光效率低成为限制实际应用的瓶颈。本项目拟将稀土上转换材料引入植物体内pH检测，设计上转换纳米粒子连接pH敏感型染料作为荧光探针，并通过物理和化学手段共同增强检测效果。制备多层光子晶体结构复合探针，通过物理长程电磁场调控增强上转换荧光。结合化学手段对上转换纳米粒子进行核壳结构设计，准确控制能量传递有效作用距离，提高共振能量传递效率，共同提高pH检测灵敏度。本项目将为油菜菌核病致病机理研究提供重要技术手段与实验基础。

Sclerotinia of rape caused by sclerotinia sclerotiorum is one of the important reasons for the decrease of rapeseed production. The study on the pathogenicity of sclerotinia sclerotiorum establishes foundation for the research and development of disease prevention and control technology. The change of intracellular pH is a response to plant development. The detection of cellular pH is imperative approach for the pathological research. Rare earth ions doped upconversion materials have demonstrated broad application potentials in the field of biomedical application. Because of the advantages of near-infrared excitation, they become a research hotspot of the highly selective detection in biological model. However, the lower luminescent efficiency is the key factor limiting its practical application. This project is proposed using rare earth doped upconversion materials into the pH detection of plants. And the upconversion nanoparticle linked to pH sensitive dyes is designed as fluorescent probes, employing fluorescence resonance energy transfer effect between upconversion nanoparticles and dyes. Based on the background of luminescent efficiency, physical and chemical methods were used to achieve the upconversion luminescence enhancement, and improve the detection limit. The photonic crystal effect of physical enhancement mechanism and the surface coating of chemical enhancement mechanism are used for enhancing upconversion luminescence synergistically. This project will offer important technical measures and experimental foundation for the pathogenic mechanism of sclerotinia sclerotiorum.