Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, People's Republic of China.
Engineering Research Center for Pharmaceuticals and Equipments of Sichuan Province, People's Republic of China.
J Pharm Biomed Anal. 2023 May 30;229:115344. doi: 10.1016/j.jpba.2023.115344. Epub 2023 Mar 15.
In this work, a novel nitrogen (N)-doped carbon dots (N-CDs) was prepared with quercetin as the carbon source and o-phenylenediamine as the nitrogen source by hydrothermal synthesis, and their application as fluorophores for selective and sensitive determination of oxytocin were reported. The fluorescence quantum yield of the as-prepared N-CDs, which exhibited good water solubility and photostability, was about 6.45 % using rhodamine 6 G as reference substance, and the maximum excitation (E) and emission (E) wavelength were 460 nm and 542 nm, respectively. The results illustrated that the direct fluorescence quenching of N-CDs fluorophore for the detection of oxytocin achieved good linearity in the range of 0.2-5.0 IU/mL and 5.0-10.0 IU/mL, the correlation coefficients were 0.9954 and 0.9909, respectively, and the detection limit was 0.0196 IU/mL (S/N = 3). The recovery rates were 98.8∼103.8 % with RSD= 0.93 %. The interference experiments showed that common metal ions, possible impurities introduced in production and coexisting excipients in the preparation had little adverse influence on selective detection of oxytocin by the developed N-CDs based fluorescent detection method. The mechanism study on the fluorescence quenching of N-CDs by oxytocin concentrations under the given experimental conditions demonstrated that there were internal filtration effect and static quenching in the system. The developed fluorescence analysis platform for the detection of oxytocin had been proved to be rapid, sensitive, specific and accurate, and to be used for the quality inspection of oxytocin.
在这项工作中，我们以槲皮素为碳源，邻苯二胺为氮源，通过水热合成法制备了一种新型氮掺杂碳点（N-CDs），并将其作为荧光团用于催产素的选择性和灵敏测定。所制备的 N-CDs 的荧光量子产率约为 6.45%，以罗丹明 6G 为参比物质，最大激发（E）和发射（E）波长分别为 460nm 和 542nm，具有良好的水溶性和光稳定性。结果表明，N-CDs 荧光团对催产素的直接荧光猝灭检测在 0.2-5.0IU/mL 和 5.0-10.0IU/mL 范围内具有良好的线性关系，相关系数分别为 0.9954 和 0.9909，检测限为 0.0196IU/mL（S/N=3）。回收率为 98.8%-103.8%，RSD=0.93%。干扰实验表明，常见金属离子、生产中可能引入的杂质和制备过程中存在的共存辅料对基于 N-CDs 荧光检测法选择性检测催产素的影响很小。在给定实验条件下，催产素浓度对 N-CDs 荧光猝灭的机制研究表明，体系中存在内滤效应和静态猝灭。所建立的用于检测催产素的荧光分析平台具有快速、灵敏、特异性好、准确性高的特点，可用于催产素的质量检验。
