基于磁性材料Co3O4纳米电化学传感器快速测定食品中的痕量苯并[a]芘

Rapid Determination of Trace Benzo[a]pyrene in Food Based on Magnetic Material Co3O4 Nano-electrochemical Sensor

摘要:

以乙炔黑（AB）、磁性Co3O4纳米颗粒、羧基化碳纳米管（MWCNTs-COOH）复合修饰材料，制备了AB@Co3O4 @MWCNTs-COOH纳米电化学传感器并构建食品中BaP痕量检测方法。采用循环伏安法（CV）对BaP在不同传感器上的电化学反应过程进行测定，发现BaP有良好的氧化峰，无还原峰，这说明其属于不可逆电化学反应过程。采用扫描电镜（SEM）、循环伏安法（CV）和交流阻抗法（EIS）对传感器进行表征，对实验条件进行了优化，结果如下：电解质溶液为0.3 mol/L高氯酸锂溶液（pH值= 2），修饰液比例为VCo3O4@MWCNTs-COOH:VAB=2:1，修饰液体积为6 μL，富集时间为15 min。在最优条件下BaP的氧化峰电流值与其浓度呈现良好的线性关系，线性回归方程为Ip=3.1939CBaP+1.5439，（R2=0.996），检出限为3.12×10-10 mol/L，加标回收率为85.7 % ~ 94.21 %。该传感器具有操作简便、检测限低、抗干扰性强、稳定性好等特点，适用于食品中BaP的现场快速筛查与定量分析。

Abstract:

An AB@Co3O4@MWCNTs-COOH electrochemical sensor for rapid detection of trace BaP in foods was prepared. The electrochemical reaction of BaP on various sensors was determined by cyclic voltammetry (CV), exhibiting a well-defined oxidation peak but no reduction peak, indicating that is irreversible oxidation-reduction process. AB@Co3O4@MWCNTs-COOH sensor were characterized by Scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The experimental conditions were optimized, the results as follow: electrolyte solution, 0.3 mol/L lithium perchlorate solution (pH=2); Modification solution composition, VCo3O4@MWCNTs-COOH: VAB=2:1; Cosmetic volume: 6 μL; Enrich time: 15 minutes. Under optimal conditions, the oxidation peak current has a well linear increases with BaP concentration (Ip=3.1939CBaP+1.5439, R2=0.996), with LOD is 3.12×10-10 mol/L and recovery rates ranged from 85.7 % to 94.21 %. The developed method was utilized to determine the content of BaP in food samples, and the results obtained are consistent with those from other methods. It was practical to determinate the content of BaP in foods with is easy to operate, had a low detection limit, good anti-interference ability, good stability, and was suitable for on-site quantitative analysis of BaP in food.