组成图示
示意图生成中
传感器类型
电化学生物传感器
检测对象
过氧化氢（hydrogen peroxide，H2O2）；样品基质：磷酸盐缓冲液、雨水、染发剂、灭菌牛奶
检测原理
HRP催化H2O2还原：H2O2 + 2H+ + HRPred → HRPox + 2H2O；HRPox氧化TTF：HRPox + 2TTF → HRPred + 2TTF+；TTF+在电极0.00 V被还原：2TTF+ + 2e− → 2TTF。TTF作为电子穿梭介体，包埋于GA交联三维聚集体，靠近MPA-SAM缺陷通道，降低背景电流并增强电子转移。H2O2浓度增加时，HRP催化产生更多TTF+，电极还原电流增大，安培峰高与浓度成正比。无酶或无TTF时信号显著降低，说明介体电子转移优于直接电子转移。
检测灵敏度
LOD: 6.9 × 10−8 mol L−1；线性范围: 2.0 × 10−7–1.0 × 10−4 mol L−1；斜率: (2.33 ± 0.02) × 10−2 A mol−1 L；r = 0.999
效应效果
选择性良好：葡萄糖、果糖、尿素、对乙酰氨基酚、尿酸在1:20摩尔比下无干扰；抗坏血酸和L-半胱氨酸在H2O2:干扰物摩尔比为2时误差<10%。重现性好：50次进样RSD 2.7%，10次校准RSD 5.2%，5电极RSD 5.3%，寿命13天，17天保留80%。牛奶加标回收(99±2)%（RSD 1.9%），牛奶LOD 7.2×10−7 mol L−1。雨水、染发剂与Mottola法无显著差异，RSD更低（3.7%对10.4%、6.5%对9.1%）。适合流动注射快速分析，75样品/小时，可用于食品工业。
传感器的构成
- 工作电极基底：金盘电极（AuE，3 mm Ø），提供导电基底与电子转导界面。
- 自组装单分子层：巯基丙酸（MPA）SAM，修饰AuE表面，降低背景电流并允许缺陷通道电子转移。
- 介体/信号标记物：四硫富瓦烯（TTF，1 μmol），先沉积于MPA-SAM上，作为可逆氧化还原介体传递电子。
- 识别/催化元件：辣根过氧化物酶（HRP，24.3 U），催化H2O2还原，是生物识别/催化元件。
- 交联固定层：戊二醛（GA，25%），交联HRP并形成三维聚集体，包埋TTF，提高固定稳定性。
- 电化学检测池：Ag/AgCl|KCl参比电极与Pt对电极，配合Autolab PSTAT 10完成安培测量。
中文摘要
本文报道了一种用于过氧化氢的集成安培生物传感器的构建及其在流动注射条件下的性能。该生物电极以巯基丙酸（MPA）自组装单分子层（SAM）修饰的金盘电极为基底，通过戊二醛交联将辣根过氧化物酶（HRP，24.3 U）与介体四硫富瓦烯（TTF，1 μmol）共同固定于SAM表面，TTF被包埋于形成的三维聚集体中。在0.05 mol/L磷酸盐缓冲液（pH 7.0）中，施加电位0.00 V，流速1.40 mL/min，进样体积150 μL时，传感器可获得可重复的流动注射安培响应。过氧化氢线性范围为2.0×10^-7–1.0×10^-4 mol/L，斜率(2.33±0.02)×10^-2 A mol^-1 L，r=0.999；检出限6.9×10^-8 mol/L；对5.0×10^-5 mol/L H2O2连续50次进样的RSD为2.7%。固定方法重现性好，5个不同电极RSD为5.3%；单个传感器使用寿命约13天。该SAM基传感器用于雨水和染发剂中过氧化氢测定，结果与分光光度参考方法比较验证，并测试了灭菌牛奶中过氧化氢加标回收。
英文摘要
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.