通过改进的hummers法合成氧化石墨烯,将氧化石墨烯(GO)分散液滴涂至玻碳电极表面,然后利用电聚合法将聚溴酚蓝(PBPB)修饰到电极上,成功制备出PBPB-GO复合膜修饰的NO^-₂检测电极。利用扫描电镜对电极材料的形貌进行表征,并对NO^-₂在复合材料上的电化学氧化机理进行了探讨。采用计时电流法对NO^-₂进行定量检测。结果表明,制备的复合膜修饰电极响应电流与NO^-₂浓度在1.0×10^-6~1.0×10^-2 mol/L范围内呈良好的线性关系,检出限为6.41×10^-7 mol/L(S/N=3),电极稳定性高、重现性好、抗干扰能力强。依据国标法提取榨菜中的亚硝酸盐,用该复合电极对其进行加标回收实验,加标回收率为104.90%~112.80%,与分光光度法相比,该法的相对误差为3.49%~9.43%。

Graphene oxide (GO) is synthesized through the modified Hummers method,and graphene oxide dispersed droplets are coated on the surface of glass carbon electrode,which are then modified by polybromophenol blue (PBPB) through electro-polymerization to obtain PBPB-GO composite membrane modified electrode for NO^-₂ detection.The morphology of the electrode material is characterized by means of scanning electron microscope.The electrochemical oxidation mechanism of NO^-₂ on the composite is explored.NO^-₂ is quantitatively detected by means of chronoamperometry.Results show that the response current of the prepared composite membrane modified electrode shows a good linear relationship with NO^-₂ concentration in the range of 1.0×10^-6-1.0×10^-2 mol·L^-1,and the detection limit is 6.41×10^-7 mol·L^-1 (S/N=3).The electrode has high stability,good reproducibility and strong anti-interference ability.According to China's national standard method,the nitrite in pickled mustard is extracted,and used to perform the spiked recovery test by the composite electrode.The recovery rates are in the range of 104.90%-112.80%,and the relative errors are in the range of 3.49%-9.43% compared with spectrophotometry.

李林(1999-),男,硕士生,研究方向为电化学传感器,1012924400@qq.com;颜家保(1964-),男,硕士,教授,研究方向为废水生物强化、深度处理及在线监测,通讯联系人,972787445@qq.com。