School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, China.
Mikrochim Acta. 2020 Jan 2;187(1):83. doi: 10.1007/s00604-019-3828-4.
A fluorometric and electrochemical dual-mode method is described for sensitive and specific detection of tetracycline (Tc). A novel nanoprobe was designed that is making use of a Tc-specific aptamer (apta), carbon nitride quantum dots (CNQDs) and silver nanoparticles (AgNPs). The aptamer was linked to the CNQDs which then were used as templates to synthesize the apta-CNQD@AgNP nanocomposites. The blue fluorescence of the nanocomposites (with excitation/emission maxima at 365/440 nm) is quenched. The addition of Tc leads to fluorescence recovery and a decrease in the electroconductivity of a gold electrode modified with apta-CNQD@AgNPs. The fluorometric method has a linear response in the 0.1 μM - 10 mM Tc concentration range and a 15 nM detection limit. The amperometric method (best performed at a working voltage of 0.21 V vs. Ag/AgCl) has a linear response in the 1 nM to 0.1 mM Tc concentration range and a 0.26 nM detection limit. Recoveries of Tc from spiked milk samples were comparable to data obtained by HPLC. Graphical abstractA fluorometric and electrochemical dual-mode nanoprobe (apta-CNQD@AgNPs) was prepared from aptamer (apta), carbon nitride quantum dots (CNQDs) and silver nanoparticles (AgNPs). The nanoprobe can be used for determination of tetracycline (Tc) based on fluorescence recovery of apta-CNQD@AgNPs and a decrease in the electroconductivity of a gold electrode modified with apta-CNQD@AgNPs.
一种荧光和电化学双模方法被用于四环素（Tc）的灵敏和特异检测。设计了一种新的纳米探针，它利用 Tc 特异性适配体（apta）、氮化碳量子点（CNQDs）和银纳米颗粒（AgNPs）。将适配体连接到 CNQDs 上，然后将其用作模板合成 apta-CNQD@AgNP 纳米复合材料。纳米复合材料的蓝色荧光（激发/发射最大值为 365/440nm）被猝灭。加入 Tc 会导致荧光恢复和修饰有 apta-CNQD@AgNPs 的金电极电导率降低。荧光法在 0.1μM-10mM Tc 浓度范围内呈线性响应，检测限为 15 nM。安培法（在相对于 Ag/AgCl 的 0.21V 工作电压下表现最佳）在 1nM 至 0.1mM Tc 浓度范围内呈线性响应，检测限为 0.26 nM。从添加牛奶样品中回收的 Tc 与 HPLC 获得的数据相当。
