将合成的立方体纳米氧化亚铜用于修饰玻碳电极,在其上固定葡萄糖氧化酶,构建了高灵敏的安培型葡萄糖生物传感器。采用X射线衍射(XRD)、扫描电镜(SEM)对合成的立方体纳米氧化亚铜及其修饰电极进行了表征。结果表明,合成的纳米氧化亚铜为均匀的立方体形状。采用循环伏安法(CV)、交流阻抗谱(EIS)、差分脉冲伏安法(DPV)及计时电流法(CA)考察了修饰电极的电化学行为。在含0.1 mmol/L葡萄糖的磷酸盐缓冲溶液(p H 7.4)中研究了立方体纳米氧化亚铜修饰电极的循环伏安(CV)响应,实验结果表明,此修饰电极对葡萄糖显示出良好的电催化性能。DPV响应电流与葡萄糖的浓度在5.0×10^(-6)~4.0×10^(-3)mol/L范围内呈良好的线性关系,线性相关系数R^2=0.9983,检出限为6.8×10^(-7)mol/L(S/N=3)。CA实验结果表明,尿酸、抗坏血酸、D-果糖对传感器不产生干扰。本传感器具有较好的重现性和稳定性,可用于实际样品中葡萄糖的检测。
An improved acetylcholinesterase liquid crystal(LC) biosensor has been developed for the identification of organophosphates(OPs) by using a reactivator. When the acetylcholinesterases(AChEs) inhibited by different kinds of OPs are reactived by a reactivator, the catalytic activity of AChEs can be recovered with different activation efficiency because of the different phosphorylation structures formed in the inhibited AChEs. Accordingly, the reactived AChEs can catalyze the hydrolysis of acetylthiocholine to generate thiocholine product in different degrees, which will result in different catalytic growth of AuNPs and further form distinct orientational response of LCs. Based on such a reactivation mechanism, the AChE LC biosensor with a simple, rapid and visual procedure achieves an obvious identification of three OPs pesticides, methamidophos, trichlorfon and paraoxon, by using a pralidoxime reactivator.
