橘色荧光碳点用于检测亚硝酸盐

Orange Luminescent Carbon Dots as Fluorescent Probe for Detection of Nitrite

以对苯二胺和柠檬酸为原料,采用一步水热法合成了氮掺杂的橘色荧光碳点(N-CDs)。通过透射电子显微镜、红外光谱、紫外-可见吸收光谱及荧光光谱对其形貌、结构和光学性质进行表征。结果表明,合成的N-CDs具有极小的尺寸((1.62±0.35) nm),以及良好的水溶性和优异的光稳定性。亚硝酸盐(NO^-_2)可使N-CDs的荧光增强。基于此,建立了一种检测NO^-_2的荧光分析新方法。本方法对NO^-_2具有良好的选择性和较高的灵敏度,测定NO^-_2的线性范围为8～100μmol/L,检出限为0.65μmol/L(S/N=3)。对可能的荧光增强的机理进行了推测,并进一步将构建的荧光传感系统应用于火腿肠、袋装咸菜和自来水样品中NO^-_2的检测,结果令人满意。

Orange luminescent nitrogen doped carbon dots(N-CDs)were prepared via one-step hydrothermal treatment by using p-phenylenediamine and citric acid as precursors.The morphology and optical properties of the N-CDs were characterized by transmission electron microscopy,fourier transform infrared spectra,ultraviolet-visible absorption spectroscopy and fluorescence spectroscopy.The results showed that the synthesized N-CDs had an extreme small size((1.62±0.35)nm),good water solubility and excellent fluorescent stability.The addition of nitrite(NO-2)caused a fluorescence increase of N-CDs.Based on this phenomenon,a new fluorescence analysis method for detecting NO-2 was established.The linear range for detection of nitrite was 8-100μmol/L,and the detection limit was 0.65μmol/L.The possible fluorescence enhancement mechanism was presented.Furthermore,the constructed fluorescence sensing system was applied to the detection of NO-2 in sausage,pickle and tap water samples with satisfactory results.