Campuzano Susana, Pedrero María, Pingarrón José M
Dpto. Química Analítica, Facultad de CC. Químicas, Universidad Complutense de Madrid, E-28040 Madrid, Spain.
Talanta. 2005 Jun 15;66(5):1310-9. doi: 10.1016/j.talanta.2005.01.048.
The construction and performance under flow-injection conditions of an integrated amperometric biosensor for hydrogen peroxide is reported. The design of the bioelectrode is based on a mercaptopropionic acid (MPA) self-assembled monolayer (SAM) modified gold disk electrode on which horseradish peroxidase (HRP, 24.3U) was immobilized by cross-linking with glutaraldehyde together with the mediator tetrathiafulvalene (TTF, 1mumol), which was entrapped in the three-dimensional aggregate formed. The amperometric biosensor allows the obtention of reproducible flow injection amperometric responses at an applied potential of 0.00V in 0.05molL(-1) phosphate buffer, pH 7.0 (flow rate: 1.40mLmin(-1), injection volume: 150muL), with a range of linearity for hydrogen peroxide within the 2.0x10(-7)-1.0x10(-4)molL(-1) concentration range (slope: (2.33+/-0.02)x10(-2)Amol(-1)L, r=0.999). A detection limit of 6.9x10(-8)molL(-1) was obtained together with a R.S.D. (n=50) of 2.7% for a hydrogen peroxide concentration level of 5.0x10(-5)molL(-1). The immobilization method showed a good reproducibility with a R.S.D. of 5.3% for five different electrodes. Moreover, the useful lifetime of one single biosensor was estimated in 13 days. The SAM-based biosensor was applied for the determination of hydrogen peroxide in rainwater and in a hair dye. The results obtained were validated by comparison with those obtained with a spectrophotometric reference method. In addition, the recovery of hydrogen peroxide in sterilised milk was tested.
报道了一种用于过氧化氢的集成安培生物传感器在流动注射条件下的构建及性能。该生物电极的设计基于巯基丙酸（MPA）自组装单层（SAM）修饰的金盘电极，在其上通过与戊二醛交联将辣根过氧化物酶（HRP，24.3U）与媒介体四硫富瓦烯（TTF，1μmol）一起固定，TTF被包埋在形成的三维聚集体中。该安培生物传感器在0.05molL⁻¹pH 7.0的磷酸盐缓冲液中，施加电位为0.00V时（流速：1.40mLmin⁻¹，进样体积：150μL），可获得可重现的流动注射安培响应，过氧化氢的线性范围在2.0×10⁻⁷ - 1.0×10⁻⁴molL⁻¹浓度范围内（斜率：(2.33±0.02)×10⁻²Amol⁻¹L，r = 0.999）。对于5.0×10⁻⁵molL⁻¹的过氧化氢浓度水平，检测限为6.9×10⁻⁸molL⁻¹，相对标准偏差（n = 50）为2.7%。固定化方法显示出良好的重现性，五个不同电极的相对标准偏差为5.3%。此外，单个生物传感器的有效寿命估计为13天。基于SAM的生物传感器用于测定雨水中和染发剂中的过氧化氢。通过与分光光度参考方法获得的结果进行比较，验证了所得结果。此外，还测试了灭菌牛奶中过氧化氢的回收率。
