Chen Dongfei, Sun Xia, Guo Yemin, Qiao Lu, Wang Xiangyou
School of Agriculture and Food Engineering, Shandong University of Technology, NO. 12, Zhangzhou Road, Zibo, 255049, Shandong Province, People's Republic of China.
Bioprocess Biosyst Eng. 2015 Feb;38(2):315-21. doi: 10.1007/s00449-014-1270-x. Epub 2014 Aug 22.
A sensitive amperometric acetylcholinesterase (AChE) biosensor was developed based on the nanocomposite of multi-walled carbon nanotubes (MWCNTs), tin oxide (SnO2) nanoparticles and chitosan (CHIT). Acetylcholinesterase (AChE) and Nafion were immobilized onto the nanocomposite film to prepare AChE biosensor for pesticide residues detection. The morphologies and electrochemistry properties of the surface modification were investigated using cyclic voltammetry, differential pulse voltammetry, and scanning electron microscopy, respectively. Compared with individual MWCNTs-CHIT, SnO2-CHIT and bare gold electrode, this nanocomposite showed the most obvious electrochemical signal in the presence of Fe(CN)6 as a redox couple. Incorporating MWCNTs and SnO2 into 0.2% CHIT solution can promote electron transfer, enhance the electrochemical response, and improve the microarchitecture of the electrode surface. All variables involved in the preparation process and analytical performance of the biosensor were optimized. Under optimized conditions, the AChE biosensor exhibited a wide linear range from 0.05 to 1.0 × 10(5 )μg/L and with a detection limit for chlorpyrifos was 0.05 μg/L. Based on the inhibition of pesticides on the AChE activity, using chlorpyrifos as model pesticide, the proposed biosensor exhibited a wide range, low detection limit, good reproducibility, and high stability. Using cabbages, lettuces, leeks, and pakchois as model samples, acceptable recovery of 98.7-105.2% was obtained. The proposed method was proven to be a feasible quantitative method for chlorpyrifos analysis, which may open a new door ultrasensitive detection of chlorpyrifos residues in vegetables and fruits.
基于多壁碳纳米管（MWCNTs）、氧化锡（SnO2）纳米颗粒和壳聚糖（CHIT）的纳米复合材料，开发了一种灵敏的安培型乙酰胆碱酯酶（AChE）生物传感器。将乙酰胆碱酯酶（AChE）和Nafion固定在纳米复合膜上，制备用于农药残留检测的AChE生物传感器。分别采用循环伏安法、差分脉冲伏安法和扫描电子显微镜研究了表面修饰的形貌和电化学性质。与单独的MWCNTs-CHIT、SnO2-CHIT和裸金电极相比，这种纳米复合材料在作为氧化还原对的Fe(CN)6存在下显示出最明显的电化学信号。将MWCNTs和SnO2加入0.2%的CHIT溶液中可以促进电子转移，增强电化学响应，并改善电极表面的微观结构。对生物传感器制备过程和分析性能中涉及的所有变量进行了优化。在优化条件下，AChE生物传感器的线性范围为0.05至1.0×10(5 )μg/L，毒死蜱的检测限为0.05 μg/L。基于农药对AChE活性的抑制作用，以毒死蜱为模型农药，所提出的生物传感器具有宽范围、低检测限、良好的重现性和高稳定性。以白菜、生菜、韭菜和小白菜为模型样品，回收率为98.7-105.2%。所提出的方法被证明是一种可行的毒死蜱定量分析方法，这可能为蔬菜水果中毒死蜱残留的超灵敏检测打开一扇新的大门。
