de Cássia Silva Luz Rita, Damos Flavio Santos, de Oliveira Adriano Bof, Beck Johannes, Kubota Lauro Tatsuo
Departamento de Quimica Analitica, Instituto de Quimica, Universidade Estadual de Campinas, Caixa Postal 6154, 13084-971 Campinas, SP, Brazil.
Talanta. 2004 Nov 15;64(4):935-42. doi: 10.1016/j.talanta.2004.04.010.
The reduction of 4-nitrophenol (4-NP) has been carried out on a modified glassy carbon electrode using cyclic and differential pulse voltammetry (DPV). The sensor was prepared by modifying the electrode with lithium tetracyanoethylenide (LiTCNE) and poly-l-lysine (PLL) film. With this modified electrode 4-NP was reduced at -0.7V versus SCE. The sensor presented better performance in 0.1moll(-1) acetate buffer at pH4.0. The other experimental parameters, such as concentration of LiTCNE and PLL, pulse amplitude and scan rate were optimized. Under optimized operational conditions, a linear response range from 27 up to 23200nmoll(-1) was obtained with a sensitivity of 3.057nAlnmol(-1)cm(-2). The detection limit for 4-NP determination was 7.5nmoll(-1). The proposed sensor presented good repeatability, evaluated in term of relative standard deviation (R.S.D.=4.4%) for n=10 and was applied for 4-NP determination in water samples. The average recovery for these samples was 103.0 (+/- 0.7)%.
采用循环伏安法和差分脉冲伏安法（DPV）在修饰玻碳电极上实现了对4-硝基苯酚（4-NP）的还原。通过用四氰基乙烯锂（LiTCNE）和聚-L-赖氨酸（PLL）膜修饰电极来制备传感器。利用该修饰电极，相对于饱和甘汞电极（SCE），4-NP在-0.7V时被还原。该传感器在pH4.0的0.1molL⁻¹醋酸盐缓冲液中表现出更好的性能。对LiTCNE和PLL的浓度、脉冲幅度和扫描速率等其他实验参数进行了优化。在优化的操作条件下，获得了27至23200nmolL⁻¹的线性响应范围，灵敏度为3.057nA/nmol⁻¹cm⁻²。4-NP测定的检测限为7.5nmolL⁻¹。所提出的传感器具有良好的重复性，以n = 10时的相对标准偏差（R.S.D.=4.4%）评估，并应用于水样中4-NP的测定。这些样品的平均回收率为103.0（±0.7）%。
