电化学方法制备石墨烯修饰电极在亚硝酸根检测中的应用

采用循环伏安法直接制备了石墨烯修饰玻碳电极并对其进行了表征,研究了亚硝酸根在石墨烯修饰玻碳电极上的电化学行为.研究结果表明:石墨烯修饰电极对亚硝酸根的氧化有良好的电催化活性,在0.10 mol·L-1PBS缓冲液(pH值为7.0)中动态安培法检测亚硝酸根的线性范围为2.69×10-6～8.13×10-4 mol·L-1和8.13×10-4～8.56×10-3 mol·L-1,灵敏度分别为42.68和10.91 μA·(mmol·L-1)-1,检出限为8.68×10-7mol·L-1(3sb).利用该方法测定了土壤样中亚硝酸根的含量,结果令人满意.

Preparation of Graphite Modified Electrode by Direct Electrochemical Method and Its Application for Determination of Nitrite

A graphite modified glassy carbon electrode was fabricated by cyclic voltammetry and was characterized with EIS and SEM techniques.Moreover,the electrochemistry behavior of nitrite was also studied on the resulting modified electrode.The results showed that the resulting modified electrode had high electrocatalytic activity to the oxidation of nitrite.Based on this,an amperometry for determation of nitrite was established in 0.10 mol·LpH 7.0 phosphate buffer solution.Under the optimum conditions,the oxidation peak current have linear relationships with concentration of nitrite over the range of 2.69×10～8.13×10 mol·L(r=0.999 7)and 8.13×10～8.56×10 mol·L(r=0.999 2)with the detection limit of 8.68×10 mol·L(3s_b).The sensitivity for the determination of nitrite was 42.68 and 10.91 μA·(mmol·L).The proposed method was applied to detect nitrite in real sample with satisfactory results.