West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu 610041, China.
West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu 610041, China; Provincial Key Laboratory for Food Safety Monitoring and Risk Assessment of Sichuan, Chengdu 610041, China.
Food Chem. 2022 May 30;377:132031. doi: 10.1016/j.foodchem.2021.132031. Epub 2022 Jan 4.
A plasma colorimetric aptasensor was developed for rapid determination of chloramphenicol (CAP) in honey on site. Herein, cage gold shell@core nanoparticles (Au@AuNPs) were synthesized to enhance signal response and broaden the linear range. In addition, aptamer-based cascade hybridization chain reaction (cHCR), consisting of HP1, HP2, HP3, and HP4, was also designed for signal amplification and specific analysis. In this assay, HP1 and HP4 were immobilized on the surface of cage Au@AuNPs. In the presence of CAP, cHCR was triggered, and frond-like DNA products were formed, which made the distance among the cage Au@AuNPs closer and the system color changed from red to deep purple. Qualitative and quantitative analysis were carried out according to color changes and UV-Vis spectra. Under the optimized conditions, the wavelength of UV-Vis absorption peak exhibited a good linear relationship with CAP concentration in the range of 5.0 to 500 nmol/L with the detection limit of 1.2 nmol/L (S/N = 3). This aptasensor also showed good specificity for CAP detection compared with other antibiotics similar to the target analyte. Furthermore, the colorimetric aptasensor was successfully applied to the detection of CAP in honey with recoveries of 88.0-107.6%. This cHCR-based aptasensing for CAP possesses high sensitivity, good selectivity, low cost and excellent stability, and could be extended to detect a wide variety of other small molecular analytes, nucleic acids or proteins. Therefore, the versatile method might become a potential alternative tool in food analysis and environmental monitoring.
现场开发了一种用于快速测定蜂蜜中氯霉素（CAP）的等离子体比色适体传感器。在此，合成了笼金壳@核纳米粒子（Au@AuNPs）以增强信号响应并拓宽线性范围。此外，还设计了基于适体的级联杂交链式反应（cHCR），由 HP1、HP2、HP3 和 HP4 组成，用于信号放大和特异性分析。在该测定中，HP1 和 HP4 固定在笼 Au@AuNPs 的表面。在存在 CAP 的情况下，触发 cHCR，形成叶状 DNA 产物，使笼 Au@AuNPs 之间的距离更近，体系颜色从红色变为深紫色。根据颜色变化和紫外-可见光谱进行定性和定量分析。在优化条件下，紫外-可见吸收峰的波长与 CAP 浓度在 5.0 至 500 nmol/L 范围内呈良好的线性关系，检测限为 1.2 nmol/L（S/N = 3）。与类似目标分析物的其他抗生素相比，该适体传感器对 CAP 的检测也表现出良好的特异性。此外，比色适体传感器成功应用于蜂蜜中 CAP 的检测，回收率为 88.0-107.6%。这种基于 cHCR 的 CAP 适体传感具有高灵敏度、良好的选择性、低成本和优异的稳定性，可扩展用于检测各种其他小分子分析物、核酸或蛋白质。因此，这种多功能方法可能成为食品分析和环境监测的潜在替代工具。
