本文利用牛血红蛋白（hemoglobin，Hb）与纳米金-还原氧化石墨烯（gold nanoparticles-reduced Graphene Oxide, AuNPs-rGO）结合修饰的玻碳电极对亚硝酸盐进行检测，通过血红蛋白对亚硝酸根（NO2-）进行还原得到高铁血红蛋白和NO3-所产生的直接电子转移信号来对NO2-进行定性和定量的检测。将AuNPs-rGO复合物修饰在玻碳电极表面，干燥后再将Hb修饰上去形成Hb/AuNPs-rGO/GCE传感器，在上述修饰的电极上涂上80 μL浓度为0.5%的Nafion，干燥后形成Nafion膜，即形成Nafion/Hb/AuNPs-rGO/GCE传感器。通过研究发现，该电极对亚硝酸盐进行循环伏安法（cyclic voltammetry, CV）检测时有良好的选择性和灵敏度，且具有较宽的线性检测范围：0.5 μM~100 μM，峰电流与硝酸盐浓度符合线性方程：IP = 0.0369C(NO2-) + 0.2245（R = 0.9918），最低检测限为0.1 μM，该方法简单、快速、灵敏，可用于环境和食品中的亚硝酸盐的检测。

Nitrite (NO2-) was detected by a glassy carbon electrode (GCE) modified by hemoglobin (Hb) with gold nanoparticle-reduced graphene oxide (AuNPs-rGO) composite. The qualitative and quantitative detection of nitrite were conducted using the signal of a direct electron transfer generated from methemoglobin and NO3- that were produced by the redox reaction between hemoglobin and nitrite. The GCE surface was modified by AuNPs-rGO composites to produce AuNPs-rGO/GCE, which was modified by Hb after drying to form an Hb/AuNPs-rGO/GCE biosensor. After the modified electrode was coated with 80 μL of 0.5% Nafion to form a Nafion film, the Nafion/Hb/AuNPs-rGO/GCE biosensor was finally obtained. The results showed that the biosensor had good selectivity and sensitivity when cyclic voltammetry method was used to detect nitrites, with a relative wide linear range from 0.5 to 100 μM. The relationship between peak current and the nitrite concentration could be described by the linear equation of IP = 0.0369C(NO2-) + 0.2245 (R = 0.9918), and the limit of detection was 0.1 μM. This method is simple, rapid, sensitive and can be used for nitrite detection in food and environmental samples.

安徽省科技厅项目（XC2014AKKG011，XC2014AKKG012）