Hasebe Yasushi, Imai Ryosuke, Hirono Masaki, Uchiyama Shunichi
Department of Applied Chemistry, Faculty of Engineering, Saitama Institute of Technology, Saitama, Japan.
Anal Sci. 2007 Jan;23(1):71-4. doi: 10.2116/analsci.23.71.
Horseradish peroxidase (HRP) and thionine (TN) were co-adsorbed onto a porous carbon felt (CF), and the resulting HRP and TN-adsorbed CF (HRP-TN-CF) was successfully used as a working electrode unit of a novel bioelectrocatalytic flow detector for a highly sensitive amperometric determination of hydrogen peroxide (H(2)O(2)). Co-adsorbed TN was essential to enhance the cathodic peak current of H(2)O(2), and the current responses of the HRP-TN-CF-based detector were much larger than those of the HRP-CF-based detector (without TN). When air-saturated 0.1 M phosphate buffer (pH 7.0) was used as a carrier at a flow rate of 3.9 ml/min, cathodic peak currents of H(2)O(2) (sample injection volume, 200 microl) obtained at an applied potential of 0 V (vs. Ag/AgCl) increased linearly up to 50 microM with a detection limit of 0.1 microM. Repetitive 100 sample injection of 100 microM H(2)O(2) induced no serious current decrease, and RSD was 0.41 to 1.21% (n = 100). The HRP-TN-CF retained 42% of its original activity after 8 days of storage in 0.1 M phosphate buffer at 4 degrees C.
将辣根过氧化物酶（HRP）和硫堇（TN）共吸附到多孔碳毡（CF）上，所得的吸附了HRP和TN的CF（HRP-TN-CF）成功用作新型生物电催化流动检测器的工作电极单元，用于高灵敏度安培法测定过氧化氢（H₂O₂）。共吸附的TN对于增强H₂O₂的阴极峰值电流至关重要，基于HRP-TN-CF的检测器的电流响应远大于基于HRP-CF的检测器（不含TN）的电流响应。当使用空气饱和的0.1 M磷酸盐缓冲液（pH 7.0）作为载体，流速为3.9 ml/min时，在0 V（相对于Ag/AgCl）的施加电位下获得的H₂O₂（进样体积200 μl）的阴极峰值电流在高达50 μM时呈线性增加，检测限为0.1 μM。对100 μM H₂O₂进行100次重复进样不会导致电流严重下降，相对标准偏差为0.41%至1.21%（n = 100）。HRP-TN-CF在4℃的0.1 M磷酸盐缓冲液中储存8天后保留了其原始活性的42%。
