Wang Shan, Liu Ruiqing, Li Chenchen
School of Chemistry and Chemical Engineering, Xianyang Normal University, Xianyang, 712000, People's Republic of China.
Nanoscale Res Lett. 2018 Aug 13;13(1):235. doi: 10.1186/s11671-018-2647-6.
In the presence of Hg, a fluorescence resonance energy transfer (FRET) system was constructed between CdSe quantum dots (QDs) (donor) and g-CN (receptors). Nanocomposites of g-CN supported by CdSe QDs (CdSe QDs/g-CN nanosheets) were fabricated through an electrostatic interaction route in an aqueous solution. The nanocomposites were characterized by X-ray photoelectron spectroscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, and transmission electron microscopy. Results showed that the g-CN nanosheets were decorated randomly by CdSe QDs, with average diameter of approximately 7 nm. The feasibility of the FRET system as a sensor was demonstrated by Hg (II) detection in water. At pH 7, a linear relationship was observed between the fluorescence intensity and the concentration of Hg (II) (0-32 nmol/L), with a detection limit of 5.3 nmol/L. The new detection method was proven to be sensitive for detecting Hg in water solutions. Moreover, the method showed high selectivity for Hg over several metal ions, including Na, Mg, Ca, Pb, Cr, Cd, Zn, and Cu. The CdSe QDs/g-CN nanosheet conjugate exhibited desirable long-term stability and reversibility as a novel FRET sensor. The novel FRET-based fluorescence detection provided an attractive assay platform for quantifying Hg in complex water solutions.
在汞存在的情况下，构建了一种在硒化镉量子点（QDs）（供体）和石墨相氮化碳（受体）之间的荧光共振能量转移（FRET）体系。通过水溶液中的静电相互作用途径制备了由硒化镉量子点支撑的石墨相氮化碳纳米复合材料（硒化镉量子点/石墨相氮化碳纳米片）。采用X射线光电子能谱、X射线衍射、傅里叶变换红外光谱和透射电子显微镜对纳米复合材料进行了表征。结果表明，石墨相氮化碳纳米片被硒化镉量子点随机修饰，平均直径约为7纳米。通过检测水中的汞（II）证明了FRET体系作为传感器的可行性。在pH值为7时，观察到荧光强度与汞（II）浓度（0 - 32 nmol/L）之间呈线性关系，检测限为5.3 nmol/L。新的检测方法被证明对检测水溶液中的汞具有敏感性。此外，该方法对汞的选择性高于包括钠、镁、钙、铅、铬、镉、锌和铜在内的几种金属离子。作为一种新型FRET传感器，硒化镉量子点/石墨相氮化碳纳米片共轭物表现出理想的长期稳定性和可逆性。基于FRET的新型荧光检测为定量分析复杂水溶液中的汞提供了一个有吸引力的检测平台。
