Carbon felt-based bioelectrocatalytic flow detectors: highly sensitive amperometric determination of hydrogen peroxide using adsorbed peroxidase and thionine.
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.
Hasebe
Yasushi
Y
Department of Applied Chemistry, Faculty of Engineering, Saitama Institute of Technology, Saitama, Japan. hasebe@sit.ac.jp
Imai
Ryosuke
R
Hirono
Masaki
M
Uchiyama
Shunichi
S
D000327:Adsorption; D002138:Calibration; D002244:Carbon; D002384:Catalysis; D004563:Electrochemistry; D017022:Flow Injection Analysis; D006735:Horseradish Peroxidase / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D010640:Phenothiazines / Q000737:chemistry*; D012834:Silver / Q000737:chemistry; D013499:Surface Properties
D007202:Indicators and Reagents; D010640:Phenothiazines; D012834:Silver; D002244:Carbon; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase; C009469:thionine