Li Xin, Jiang Xin, Liu Qingye, Liang Aihui, Jiang Zhiliang
Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Guilin 541004, China.
Ministry of Education, Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin 541004, China.
Nanomaterials (Basel). 2019 Feb 7;9(2):223. doi: 10.3390/nano9020223.
The strongly fluorescent and highly catalytic N-doped carbon dots (CD) were rapidly prepared by a microwave irradiation procedure and were characterized by electron microscopy (EM), laser scattering, infrared spectroscopy (IR), and by their fluorescence spectrum. It was found that the CD had a strong catalytic effect on the fluorescence reaction of 3,3',5,5'-tetramethylbenzidine hydroxide ((TMB)⁻H₂O₂) which produced the oxidation product of TMB (TMB) with strong fluorescence at 406 nm. The aptamer (Apt) was adsorbed on the CD surfaces which weakened the fluorescence intensity due to the inhibition of catalytic activity. When the target molecule isocarbophos (IPS) was added, it reacted with the Apt to form a stable conjugate and free CD which restored the catalytic activity to enhance the fluorescence. Using TMB as a fluorescent probe, a highly sensitive nanocatalytic method for determination of 0.025⁻1.5 μg/L IPS was established with a detection limit of 0.015 μg/L. Coupling the CD fluorescent probe with the Apt⁻IPS reaction, a new CD fluorescence method was established for the simple and rapid determination of 0.25⁻1.5 μg/L IPS with a detection limit of 0.11 μg/L.
通过微波辐照法快速制备了具有强荧光和高催化活性的氮掺杂碳点（CD），并通过电子显微镜（EM）、激光散射、红外光谱（IR）及其荧光光谱对其进行了表征。发现CD对3,3',5,5'-四甲基联苯胺氢氧化物（（TMB）⁻H₂O₂）的荧光反应具有强烈的催化作用，该反应产生在406 nm处具有强荧光的TMB氧化产物（TMB）。适配体（Apt）吸附在CD表面，由于催化活性受到抑制，导致荧光强度减弱。当加入目标分子水胺硫磷（IPS）时，它与Apt反应形成稳定的共轭物并释放出CD，从而恢复催化活性以增强荧光。以TMB为荧光探针，建立了一种测定0.025⁻1.5 μg/L IPS的高灵敏度纳米催化方法，检测限为0.015 μg/L。将CD荧光探针与Apt⁻IPS反应相结合，建立了一种新的CD荧光方法，用于简单快速地测定0.25⁻1.5 μg/L IPS，检测限为0.11 μg/L。
