Flow-through micro sensor using immobilized peroxidase with chemiluminometric FIA system for determining hydrogen peroxide.
A micromachined flow cell (overall size; 25 x 25 x 1 mm3) was designed for the fast determination of hydrogen peroxide, based on a luminol-H2O2 chemiluminescence reaction catalyzed by immobilized peroxidase (POD). The flow cell consisted of a sandwich of anisotropically etched silicon and glass chips and contained a spiral channel (20 turns, 50 cm long, 150 microm wide, 20 microm depth, channel volume 1.4 microl) and two holes (1 mm diameter). POD was covalently immobilized with 3-(trimethoxysilyl)propyldietylenetriamine and glutaraldehyde on the inner surface of the channel. The chip was placed in front of a window of a photomultiplier tube and used as a flow cell in a single-line flow-injection analysis system using a luminol solution as a carrier solution. The sample volume for one measurement was 0.2 microl. The maximal sampling rate was 315 h(-1) at a carrier solution flow rate of 10 microl min(-1). A calibration graph for H2O2 was linear for 5 nM - 5 microM; the detection limit (signal-to-noise = 3) was 1 nM (7 fg in 0.2 microl injection). The H2O2 concentration in rainwater was determined using this sensor system.
Kiba
Nobutoshi
N
Department of Applied Chemistry and Biotechnology, Faculty of Engineering, Yamanashi University, Kofu 400-851, Japan. kibat@ab11.yamanashi.ac.jp
Tokizawa
Toyonari
T
Kato
Sayaka
S
Tachibana
Masaki
M
Tani
Kazue
K
Koizumi
Hitoshi
H
Edo
Masaharu
M
Yonezawa
Eiichi
E
D002138:Calibration; D004800:Enzymes, Immobilized / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000032:analysis*; D007202:Indicators and Reagents; D008163:Luminescent Measurements; D008165:Luminol / Q000737:chemistry; D008839:Microelectrodes; D010544:Peroxidases / Q000737:chemistry*; D011891:Rain; D014874:Water Pollutants, Chemical / Q000032:analysis*
D004800:Enzymes, Immobilized; D007202:Indicators and Reagents; D014874:Water Pollutants, Chemical; D008165:Luminol; D006861:Hydrogen Peroxide; D010544:Peroxidases