L-半胱氨酸/辣根过氧化物酶/纳米银/辣根过氧化物酶修饰电极循环伏安法测定过氧化氢  

Determination of H_2O_2 by Modified Electrode Based on L-Cysteine/Horseradish Peroxidase/Nano-Ag/Horseradish Peroxidase

作　　者：马美萍[1] 曹建明[1] 连国军[1] 

机构地区：[1]温州医学院环境与公共卫生学院,浙江温州325035

出　　处：《分析测试学报》2010年第11期1165-1168,共4页Journal of Instrumental Analysis

摘　　要：在金电极表面自组装L-半胱氨酸,再分别吸附辣根过氧化物酶(HRP)和纳米银,制得L-半胱氨酸/辣根过氧化物酶/纳米银/辣根过氧化物酶修饰电极。采用循环伏安法研究了修饰电极的电化学特性,探讨了pH值、温度对电极响应的影响,考察了电极的重复性、稳定性及选择性。实验结果表明,HRP在修饰电极表面能进行有效和稳定的电子转移,HRP保持了其对H2O2还原的生物催化活性。该电极对H2O2检测的线性范围为8.6×10-7～1.3×10-3mol/L,r=0.9985,检出限(S/N=3)为1.6×10-7mol/L。该电极具有稳定性好、线性范围宽、检出限低等优点,同时具有一定的抗干扰能力。A novel hydrogen peroxide biosensor based on self-assembly of L-cysteine/HRP/nano-Ag/ HRP was developed. L-cysteine was first immobilized onto a gold electrode, HRP and silver nanoparticles were adsorbed on the L-cysteine monolayer, respectively. The electrochemical characteristics of the modified electrode was characterized by cyclic voltammetry. The results demonstrated that HRP could perform the direct electron transfer effectively on the electrode surface. The HRP displayed an excellent electrocatalytic response to the reduction of hydrogen peroxide. The effects of experimental conditions such as pH and temperature were investigated. The reproducibility, stability and selectivi- ty of the electrode were also tested. Under the optimal conditions, the electrode showed a good linear range for H2O2 between 8.6 × 10^-7 and 1.3 ×10^-3 mol.L^-1 with a correlation coefficient of 0. 998 5. The detection limit（S/N =3）was 1.6 × 10^-7 mol.L^-1. The biologic compounds such as glucose and various amino acids did not disturb the determination of H2O2. The modified electrode exhibited advanteges of good stability, wide linear range and lower detection limit as well as certain anti-interference ability.

关 键 词：H2O2 电极 L-半胱氨酸 辣根过氧化物酶 纳米银 

分 类 号：O657.1[理学—分析化学] TQ123.6[理学—化学]