氮掺杂碳点的制备及其对阿莫西林高灵敏检测

以天然物质石斛为原料,一步水热法合成高荧光量子产率的氮掺杂碳点(NCDs),通过透射电子显微镜(TEM)、X射线光电子能谱(XPS)、傅里叶变换红外光谱(FT-IR)、紫外-可见光吸收图谱(UV-Vis)及荧光光谱(PL)对合成的NCDs进行表征。 实验结果显示合成的NCDs发强烈的蓝色荧光,呈现为球形或准球形,均匀分散,尺寸范围在1~5 nm;其表面含有丰富的COOH、OH和NH₂等水溶性基团,最佳激发和发射波长分别为350和435 nm,且具有良好的发光稳定性。 通过测定,合成的NCDs的荧光量子产率高达29.19%。在pH=7.4的缓冲溶液中测定不同物质对NCDs的荧光影响,相同条件下发现只有阿莫西林能够对NCDs荧光进行明显猝灭,表明合成的NCDs可选择性的识别阿莫西林,通过NCDs的荧光强度变化构建一种可灵敏检测阿莫西林的传感器,检测线性范围为2.6~30 μmol/L,检出限为0.15 μmol/L。

Preparation of Nitrogen-Doped Carbon Dots for Highly Sensitive Detection of Amoxicillin

In this paper,the nitrogen-doped carbon dots(NCDs)were synthesized using the natural material dendrobe as the raw material by one-step hydrothermal method.The synthesized carbon dots were characterized by transmission electron microscopy(TEM),X-ray photoelectron spectroscopy(XPS),Fourier transform infrared(FTIR)spectroscopy,ultraviolet-visible(UV-Vis)absorption spectroscopy and photoluminescence spectroscopy(PL).The experiment results show that NCDs are spherical or quasi-spherical,uniformly dispersed with the size ranges from 1 to 5 nm,which can emit strong blue fluorescence.The surface of the synthesized NCDs is rich in water-soluble groups such as COOH,OH and NH 2.The optimal excitation and emission wavelengths of NCDs are 350 and 435 nm,respectively.Meanwhile,the fluorescence emission has good luminescence stability.The fluorescence quantum yield of the carbon dots is as high as 29.19%.The effects of different substances on the fluorescence of NCDs were measured in a buffer solution with pH=7.4.Under the same conditions,only amoxicillin is able to significantly quench the fluorescence of NCDs,indicating the synthesized NCDs can selectively interact with amoxicillin.A sensitive sensor was constructed for detecting amoxicillin by changing the fluorescence intensity of carbon dots.The linear detection range for amoxicillin is from 2.6 to 30μmol/L and the detection limit is 0.15μmol/L.