上转换稀土纳米发光材料二次激发过渡金属配合物检测生物巯基小分子的研究

Small-molecular-weight biological thiols, as a class of molecules containing free thiol moieties, for instance cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), etc., play various essential roles in many physiological processes. Therefore, novel fluorescent sensors of simplicity, specificity and sensitivity are required to related diseases' prophylactical and early treatment. We plan to design several assembled fluorescent nanosensors based on resonance energy transfer between lanthanide-doped β-NaYF4 upconversion nanophosphors as an energy donor and transition-metal complexes as an energy acceptor. Herein the transition-metal complexes are used as phosphorescent probes for the sensitive and selective detection of bio-thiols. The upconversion nanophosphors are used as both the carriers and the secondary excitation sources of the probes, which enable the nanosensor to exhibit weaker autofluorescence and greater penetration depth. The complexes probes for bio-thiols are covalently grafted onto the upconversion nanophosphors. A layer of polymer, if necessary, will be bound to the surface of the nanosensor as the selective barrier for various bio-thiols via different interactions between different bio-thiols and the polymer chains, to improve the selectivity of the nanosensor. 980 nm laser is chosen to be the excitation source of the sensor, the probe molecules will be excited by the energy from the upconversion nanophosphor core via either fluorescence resonance energy transfer (FRET) or luminescence resonance energy transfer (LRET). The target bio-thiols will be detected via the change of the spectra of the sensors before and after the probe molecules react with the target bio-thiols. The upconversion luminescence at the wavelength which is not absorbed by the probe molecules can be used as the internal standard to achieve the ratiometric detection.

含巯基的生物小分子，如半胱氨酸、高半胱氨酸等，在生命活动中发挥着至关重要的作用，开发能够简便快捷检测生物体中的各种巯基小分子含量的新型荧光探针传感器对开展相关疾病的预防和早期治疗具有重要的意义。本项目拟制备基于上转换发光二次激发过渡金属配合物的复合型纳米光化学传感材料。以对巯基小分子有特异性响应的配合物作为传感分子，共价嫁接至上转换发光纳米粒子核心上，并于材料表面修饰一层具有筛选不同巯基小分子功能的位阻基团为传感器提供更好的选择性。通过检测传感分子与巯基分子反应前后发射光谱的变化，测得样品中巯基分子的浓度。通过采用上转换发光纳米粒子进行二次激发，增加了激发光源的穿透深度，为体内检测提供条件；另一方面可利用其不被配合物吸收的发射波段作为内标参比，提高传感的准确性和灵敏度；同时也为传感分子提供固载基质、便于细胞内成像、实现目视比色，为开发家庭化试纸型商品提供可能。

含巯基的生物小分子，如半胱氨酸、高半胱氨酸等，在生命活动中发挥着至关重要的作用，开发能够简便快捷检测生物体中的各种巯基小分子含量的新型荧光探针传感器对开展相关疾病的预防和早期治疗具有重要的意义。本项目拟制备基于上转换发光二次激发过渡金属配合物的复合型纳米光化学传感材料。以对巯基小分子有特异性响应的配合物作为传感分子，共价嫁接至上转换发光纳米粒子核心上，并于材料表面修饰一层具有筛选不同巯基小分子功能的位阻基团为传感器提供更好的选择性。通过检测传感分子与巯基分子反应前后发射光谱的变化，测得样品中巯基分子的浓度。通过采用上转换发光纳米粒子进行二次激发，增加了激发光源的穿透深度，为体内检测提供条件；另一方面可利用其不被配合物吸收的发射波段作为内标参比，提高传感的准确性和灵敏度；同时也为传感分子提供固载基质、便于细胞内成像、实现目视比色，为开发家庭化试纸型商品提供可能。