【摘要】 具有长波长荧光发射特性的碳点（CDs）材料由于其在生物领域的广阔应用而受到越来越多的关注。长波长发射荧光碳点的合成主要基于高温高压的方法，室温合成的方法和研究还比较少。采用碱催化的方式，将氢氧化钠溶液与果糖溶液混合后透析，无需加热和其他额外的能量输入即可制备出一种蓝绿色发光可调的碳点，并通过透射电子显微镜、紫外-可见分光光度计、稳态荧光光谱仪等光谱技术对合成碳点进行了表征。进一步采用圆二色分光光度计和皮秒时间相关单光子计数等测量系统对碳点与牛血红蛋白（BHb）之间的相互作用进行了探究。虽然已有较多应用碳点检测BHb的研究，但这些研究更注重分析BHb检测的效果，而对BHb猝灭碳点荧光的机理还缺少较为详细的系统性证明。测量得到了二者在不同温度下相互作用的Stern-Volmer图像，以及碳点在BHb加入前后的荧光寿命，结果表明BHb对碳点荧光的猝灭是一个静态的过程。并且在该过程中，BHb的α-螺旋含量下降了约3%,证明了碳点会使蛋白的结构发生改变。BHb与碳点混合后形成了复合物，导致碳点的荧光下降。通过分析干扰样品以及反应时间对检测BHb的影响，证实了碳点检测BHb具有良好的选择性和稳定性。另外，碳点荧光强度下降，下降比例与BHb浓度成线性关系，因此可以设计基于碳点荧光猝灭的血红蛋白生物传感器，用于微量BHb的特异性检测，所检测的线性范围为0～5μmol·L^-1,检测限为243 nmol·L^-1（S/N=3）。所合成的碳点还可以实现双波长激发检测，实验证实在370和425 nm激发下，碳点的荧光猝灭程度和BHb的浓度之间表现出良好的线性关系，这为该荧光探针检测BHb提供了更多的应用价值。由于该碳点的合成手段简便，操作技术难度低且合成原料容易获得，该荧光探针对BHb的微量检测在生命科学研究和刑侦领域都具有十分重要的意义。更多还原

【Abstract】 Fluorescent carbon dots（CDs） with long wavelength emission have attracted increasing attention due to their promising application prospects in biological fields. CDs with long wavelength emission have been synthesized mainly with high temperature and high pressure, while their synthesis at room temperature is relatively rarely studied. In this paper, blue-green luminescent tunable CDs were prepared by alkaline catalysis, and only two steps were required. The fructose and sodium hydroxide solutions were mixed firstly, followed by dialyzing without any additional energy input or external heating. The synthesized CDs were studied by transmission electron microscopy, steady-state fluorescence, and UV-Vis absorption spectroscopy. Moreover, circular dichroic spectrophotometer and picosecond time-correlated single photon counting system was used to analyze the interaction mechanism between CDs and bovine hemoglobin（BHb）. Although there have been some studies about the detection of BHb using carbon dots, previous studies mainly focus on the detection of BHb rather than the fluorescence quenching mechanism of carbon dots. Stern-Volmer imagesof the interaction and the influence of BHb on the fluorescence lifetime of CDs have been measured, implying the contribution of static fluorescence quenching. In this process, the content of the α-helical structure of BHb has decreasedby about 3%, demonstrating that the secondary structures of BHb were changed after interacting with CDs. With the addition of BHb, the complexes of BHb and CDs were formed so the fluorescence of CDs decreased. Moreover, the addition of interference samples in the experiment of BHb detection confirmed that the proposed CDs were highly selective, and the variation of reaction times further revealed that the CDs had high stability. It is noticed that, when mixed with BHb, the fluorescence intensity of CDs decreased gradually, and the proportion of decline was linearly related to the concentrations of BHb. Therefore, the biosensors based on CD fluorescence quenching could be established for the specific detection of trace BHb with a linear concentration range from 0 to 5 μmol·L^-1 and a detection limit of 243 nmol·L^-1（S/N=3）. The CDs were also excited with different wavelengths at 370 and 425 nm, and the results proved that the fluorescence intensities of CDs had a good linear relationship with the concentrations of BHb for both excitation wavelengths, which might provide more application values for the detection of BHb. Due to its convenient synthesis, simple operation and easy availability, the proposed CD probe is of great significance in life sciences and criminal investigation.更多还原