Damos Flavio Santos, Sotomayor Maria del Pilar Taboada, Kubota Lauro Tatsuo, Tanaka Sônia Maria C N, Tanaka Auro Atsushi
Departamento de Química, Universidade Federal do Maranhão, São Luís, MA, Brazil.
Analyst. 2003 Mar;128(3):255-9. doi: 10.1039/b207894e.
The use of iron(III) tetra-(N-methyl-4-pyridyl) porphyrin (FeIIIT4MpyP) and histidine (His) in the construction of an amperometric sensor for phenolic compound determinations is reported, based on horseradish peroxidase (HRP) chemistry. The sensor was prepared by modifying a glassy carbon electrode with Nafion membrane doped with FeIIIT4MpyP and His, in a mass ratio of 1:2. The sensor presented its best performance at 50 mV vs. SCE in 0.1 mol l(-1) succinate buffer (pH = 4.0) containing 125 micromol l(-1) H2O2. Under optimized operational conditions, a linear response range from 0.6 to 6.0 micromol l(-1) was obtained with a sensitivity of 61 nA cm(-2) micromol l(-1). The detection limit for catechol determination was 0.35 micromol l(-1). The response time was less than 0.5 s. The proposed sensor presented stable responses for 100 successive determinations, while satisfactory responses were observed even after 200 measurements. The repeatability, evaluated in terms of relative standard deviation, was 4% for n = 7. The signal responses for other phenolic compounds, including those of environmental and clinical interest, were also investigated.
报道了基于辣根过氧化物酶（HRP）化学原理，利用铁（III）四 - （N - 甲基 - 4 - 吡啶基）卟啉（FeIIIT4MpyP）和组氨酸（His）构建用于测定酚类化合物的电流型传感器。该传感器通过用掺杂有质量比为1:2的FeIIIT4MpyP和His的Nafion膜修饰玻碳电极制备而成。该传感器在含有125 μmol l(-1) H2O2的0.1 mol l(-1)琥珀酸盐缓冲液（pH = 4.0）中，相对于饱和甘汞电极（SCE）在50 mV时表现出最佳性能。在优化的操作条件下，获得了0.6至6.0 μmol l(-1)的线性响应范围，灵敏度为61 nA cm(-2) μmol l(-1)。儿茶酚测定的检测限为0.35 μmol l(-1)。响应时间小于0.5 s。所提出的传感器在100次连续测定中呈现出稳定的响应，即使在200次测量后也观察到令人满意的响应。以相对标准偏差评估的重复性，n = 7时为4%。还研究了其他酚类化合物的信号响应，包括那些具有环境和临床意义的化合物。
