基于氮掺杂碳球生长金的酶传感器检测蔬菜中的克百威

以氮掺杂碳球(nitrogen doped carbon spheres,N-Cs)为基质,制备新型的氮掺杂碳球生长金纳米复合材料(N-Cs-Au),采用交联法制备新型的基于N-Cs-Au修饰玻碳电极(glassy carbon electrode,GCE)的乙酰胆碱酯酶(acetylcholinesterase,AChE)生物传感器(AChE/N-Cs-Au/GCE)并用于菠菜中克百威的定量分析。结果表明:N-Cs-Au具有较好的导电性和电催化活性,能够有效地促进电子转移,提高AChE/N-Cs-Au/GCE的灵敏度。利用AChE/N-Cs-Au/GCE对菠菜中的克百威进行检测分析,克百威质量浓度的负对数与其对AChE/N-Cs-Au/GCE的抑制率在2.3×10~(-10)~2.3×10~(-5) g/L的线性范围内呈良好的线性关系,线性方程为Y/%=-8.246 7X+93.867 6(X为克百威质量浓度的负对数),R2为0.992 9,按抑制率10%计算,检出限为6.763 9×10~(-11) g/L,用AChE/N-Cs-Au/GCE对菠菜中的克百威进行检测分析,样品回收率在91.417 7%~95.859 7%之间,精密度较高,符合实验要求,且该传感器对常见的重金属Pb、Cu、Cd和Mn有较好的抗干扰能力,为食品中克百威的检测提供了一种新方法。

Development of Acetylcholinesterase Biosensor for Detection of Carbofuran in Vegetables Based on Nitrogen-Doped Carbon Sphere-Gold Nanoparticles Composite Modified Electrode

An acetylcholinesterase (AChE) biosensor was prepared by cross-linking AChE and bovine serum albumin (BSA) onto nitrogen doped carbon sphere-gold (N-Cs-Au) nanoparticles composite modified glassy carbon electrode (GCE) and used for detecting carbofuran in spinach. The results showed that N-Cs-Au had a good electrical conductivity and catalytic activity, effectively promoting electron transfer and consequently improving the sensitivity of AChE/N-Cs- Au/GCE. It was found that there was a good linear relationship between the negative common logarithm of carbofuran concentration (X) in the range from 2.3 × 10-10 to 2.3 × 10-5 g/L and the percentage inhibition of the peak current by carbofuran (Y) as indicated by the equation: Y/% = −8.246 7X + 93.867 6 (R2 = 0.992 9). As calculated by 10% inhibition, the limit of detection (LOD) for carbofuran was 6.763 9 × 10-11 g/L. The sensor showed recoveries of 91.417 7%–95.859 7% for carbofuran in spiked spinach and high precision, which could meet the analytical requirements. Moreover, the sensor was free from the interference of common heavy metals such as Pb, Cu, Cd and Mn and could provide a new method for detecting carbofuran in foods.