Li Huanhuan, Geng Wenhui, Qi Zhixiong, Ahmad Waqas, Haruna Suleiman A, Chen Quansheng
School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, PR China.
School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, PR China; College of Ocean Food and Biological Engineering, Jimei University, Xiamen, 361021, PR China.
Biosens Bioelectron. 2023 Apr 15;226:115122. doi: 10.1016/j.bios.2023.115122. Epub 2023 Feb 4.
In this work, a stimuli-responsive SERS biosensor was fabricated for tetracycline (TTC) by "signal-on" strategy using (EDTA)-driven polyethyleneimine grafted calcium carbonate (PEI@CaCO) microcapsule and chitosan-Fe magnetic microbeads (CS@FeMMs). Initially, aptamer conjugated magnetic-bead CS@FeMMs@Apt with superparamagnetism and excellent biocompatibility was employed as capture probe, which facilitated the rapid and easy magnetic separation. Subsequently, the PEI cross-linked layer and aptamer network layer were constructed onto the outer layer of CaCO@4-ATP microcapsule to form sensing probes (PEI@CaCO@4-ATP@Apt) via the layer-by-layer assembly method. In the presence of TTC, a sandwich SERS-assay was exploited by aptamer recognition induced target-bridged strategy. When the solution of EDTA was added, the core layer of CaCO would be dissolved quickly, destroying the microcapsule to release 4-ATP. The released 4-ATP could be quantitatively monitored by dripping the supernatant onto the AuNTs@PDMS SERS platform, resulting in a strong Raman "signal-on". Under the optimal conditions, a good linear relationship was established with a correlation coefficient (R) of 0.9938 and a LOD of 0.03 ng/mL. Additionally, the application capacity of the biosensor to detect TTC was also affirmed in food matrixes, and the results were consistent with the standard ELISA method (P > 0.05). Hence, this SERS biosensor affords extensive application prospects for TTC detection with multiple merits such as high sensitivity, environment friendliness, and high stability.
在本研究中，采用（乙二胺四乙酸）驱动的聚乙烯亚胺接枝碳酸钙（PEI@CaCO）微胶囊和壳聚糖-铁磁性微珠（CS@FeMMs），通过“信号开启”策略制备了一种用于四环素（TTC）的刺激响应型表面增强拉曼散射（SERS）生物传感器。首先，将具有超顺磁性和优异生物相容性的适配体共轭磁珠CS@FeMMs@Apt用作捕获探针，这有助于快速简便地进行磁分离。随后，通过层层组装法在CaCO@4-ATP微胶囊的外层构建PEI交联层和适配体网络层，形成传感探针（PEI@CaCO@4-ATP@Apt）。在TTC存在的情况下，通过适配体识别诱导的靶标桥接策略开发了一种夹心SERS检测方法。当加入乙二胺四乙酸溶液时，CaCO的核心层会迅速溶解，破坏微胶囊以释放4-ATP。将上清液滴加到AuNTs@PDMS SERS平台上，可以对释放的4-ATP进行定量监测，从而产生强烈的拉曼“信号开启”。在最佳条件下，建立了良好的线性关系，相关系数（R）为0.9938，检测限为0.03 ng/mL。此外，还证实了该生物传感器在食品基质中检测TTC的应用能力，结果与标准酶联免疫吸附测定法一致（P>0.05）。因此，这种SERS生物传感器为TTC检测提供了广阔的应用前景，具有高灵敏度、环境友好和高稳定性等多种优点。
