Li Chongning, Li Jiao, Liang Aihui, Wen Guiqing, Jiang Zhiliang
State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmaceutical Science, Guangxi Normal University, Guilin, China.
Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guilin, China.
Front Chem. 2021 Mar 15;9:613083. doi: 10.3389/fchem.2021.613083. eCollection 2021.
Sensitive and selective methods for the determination of urea in samples such as dairy products are important for quality control and health applications. Using ammonium ferric citrate as a precursor, Fe/N-codoped carbon dots (CD) were prepared by a hydrothermal procedure and characterized in detail. CD strongly catalyzes the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by HO to turn on an indicator molecular reaction, forming an oxidized tetramethylbenzidine (TMB) probe with surface-enhanced Raman scattering, resonance Rayleigh scattering, and fluorescence (SERS, RRS, and FL) signals at 1,598 cm, 370 nm, and 405 nm, respectively. The urea aptamer (Apt) can turn off the indicator reaction to reduce the tri-signals, and the addition of urea turns on the indicator reaction to linearly enhance the SERS/RRS/FL intensity. Thus, a novel Apt turn-on tri-mode method was developed for the assay determination of ultra-trace urea with high sensitivity, good selectivity, and accuracy. Trace adenosine triphosphate and estradiol can also be determined by the Apt-CD catalytic analytical platform.
用于测定乳制品等样品中尿素的灵敏且选择性的方法对于质量控制和健康应用非常重要。以柠檬酸铁铵为前驱体，通过水热法制备了铁/氮共掺杂碳点（CD）并进行了详细表征。CD强烈催化HO对3,3',5,5'-四甲基联苯胺（TMB）的氧化，开启指示分子反应，形成具有表面增强拉曼散射、共振瑞利散射和荧光（SERS、RRS和FL）信号的氧化四甲基联苯胺（TMB）探针，其信号分别位于1598 cm、370 nm和405 nm处。尿素适配体（Apt）可关闭指示反应以降低三信号，而加入尿素则开启指示反应以线性增强SERS/RRS/FL强度。因此，开发了一种新型的Apt开启三模式方法，用于超痕量尿素的测定，具有高灵敏度、良好的选择性和准确性。痕量三磷酸腺苷和雌二醇也可通过Apt-CD催化分析平台进行测定。
