School of Agriculture and Food Engineering, Shandong University of Technology, NO. 12, Zhangzhou Road, Zibo, 255049, Shandong, People's Republic of China.
Bioprocess Biosyst Eng. 2013 Mar;36(3):273-83. doi: 10.1007/s00449-012-0782-5. Epub 2012 Jul 25.
In this work, a highly sensitive acetylcholinesterase (AChE) inhibition-based amperometric biosensor has been developed. Firstly, a glassy carbon electrode (GCE) was modified with chitosan (Chits). Then, hollow gold nanospheres (HGNs) were absorbed onto the surface of chitosan based on the strong affinity through electrostatic adsorption. After that, L-cysteine (L-cys) was assembled on HGNs through Au-S bond. The hollow gold nanospheres were prepared by using Co nanoparticles as sacrificial templates and characterized by scanning electron microscopy, transmission electron microscopy and ultraviolet spectra, respectively. Finally, AChE was immobilized with covalent binding via -COOH groups of L-cysteine onto the modified GCE. The AChE biosensor fabrication process was characterized by cyclic voltammetry and electrochemical impedance spectroscopy methods with the use of ferricyanide as an electrochemical redox indicator. Under optimum conditions, the inhibition rates of pesticides were proportional to their concentrations in the range of 0.1-150 and 0.1-200 μg L(-1) for chlorpyrifos and carbofuran, respectively, the detection limits were 0.06 μg L(-1) for chlorpyrifos and 0.08 μg L(-1) for carbofuran. Moreover, the biosensor exhibited a good stability and reproducibility and was suitable for trace detection of pesticide residues in vegetables and fruits.
在这项工作中，开发了一种基于乙酰胆碱酯酶 (AChE) 抑制的高灵敏度安培生物传感器。首先，将玻碳电极 (GCE) 用壳聚糖 (Chits) 修饰。然后，通过静电吸附将中空金纳米球 (HGNs) 吸附到壳聚糖表面上。之后，通过 Au-S 键将 L-半胱氨酸 (L-cys) 组装到 HGNs 上。中空金纳米球是通过 Co 纳米颗粒作为牺牲模板制备的，并分别通过扫描电子显微镜、透射电子显微镜和紫外光谱进行了表征。最后，通过 L-半胱氨酸的 -COOH 基团将 AChE 通过共价键固定在修饰的 GCE 上。AChE 生物传感器的制备过程通过循环伏安法和电化学阻抗谱法进行了表征，使用铁氰化物作为电化学氧化还原指示剂。在最佳条件下，对于毒死蜱和呋喃丹，农药的抑制率与它们在 0.1-150 和 0.1-200 μg L(-1)范围内的浓度成正比，检测限分别为 0.06 μg L(-1)和 0.08 μg L(-1)。此外，该生物传感器表现出良好的稳定性和重现性，适用于蔬菜和水果中农药残留的痕量检测。
