Key Laboratory of Interfacial Reaction & Sensing Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022, People's Republic of China.
Mikrochim Acta. 2019 Dec 18;187(1):63. doi: 10.1007/s00604-019-4012-6.
A nanocomposite was prepared from a bifunctionalized ionic liquid, chitosan on magnetic nanoparticle-modified graphene oxide (IL/Chit@MGO). It was used in a chemiluminescencc (CL) assay for tetracycline. The materials were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray powder diffraction, nitrogen adsorption-desorption isotherm, vibrating sample magnetometry and zeta potentials. Subsequently, a tetracycline-binding aptamer (TC-Apt) acting as a recognition element, and G-quadruplex DNAzyme (G-DNAzyme) acting as a signal amplification component were modified on IL/Chit@MGO. So, the bifunctional G-DNAzyme/TC-Apt/IL/Chit@MGO was prepared. The IL/Chit@MGO is found to possess excellent loading capability for TC-Apt. This is attributed to the large specific surface and abundant charge on the surface of IL/Chit@MGO. The composite was used to construct a CL assay for tetracycline. Tetracycline binds to TC-Apt and causes the release of the G-DNAzyme. The latter catalyzes the CL of luminol-HO CL system at pH 7.4. Under optimized conditions, the blue CL at the emission wavelength of 425 nm increases linearly in the 0.16 pM to 2.0 nM concentration range, and the detection limit is 21 fM (at 3σ). The assay is selective, reproducible and stable. The assay was applied to tetracycline detection in practical samples. The apparent recoveries are 98.0% to 101.3% for the milk sample and 97.0% to 102.2% for the water sample. Graphical abstractG-quadruplex DNAzyme (G-DNAzyme) and tetracycline aptamer (TC-Apt) bifunctionalized ionic liquid/chitosan@magnetic graphene oxide (IL/Chit@MGO) was prepared. The nanocomposite was used to construct a chemiluminescence (CL) assay for tetracycline.
一种由双功能离子液体、壳聚糖修饰的磁性氧化石墨烯上的纳米复合材料（IL/Chit@MGO）制备而成。它被用于四环素的化学发光（CL）测定。通过傅里叶变换红外光谱、扫描电子显微镜、X 射线粉末衍射、氮气吸附-解吸等温线、振动样品磁强计和zeta 电位对材料进行了表征。随后，将作为识别元件的四环素结合适体（TC-Apt）和作为信号放大组件的 G-四链体 DNA 酶（G-DNAzyme）修饰在 IL/Chit@MGO 上。因此，制备了双功能 G-DNAzyme/TC-Apt/IL/Chit@MGO。发现 IL/Chit@MGO 具有优异的 TC-Apt 负载能力。这归因于 IL/Chit@MGO 表面较大的比表面积和丰富的电荷。该复合材料用于构建四环素的 CL 测定。四环素与 TC-Apt 结合，导致 G-DNAzyme 释放。后者在 pH 7.4 下催化鲁米诺-HOCL 体系的 CL。在优化条件下，在 0.16 pM 至 2.0 nM 的浓度范围内，蓝色 CL 在 425nm 的发射波长处呈线性增加，检测限为 21 fM（3σ）。该测定具有选择性、重现性和稳定性。该测定法用于实际样品中四环素的检测。牛奶样品的回收率为 98.0%至 101.3%，水样的回收率为 97.0%至 102.2%。
