Determination of hydrogen peroxide in disinfectant solutions using a biosensor with two antagonist enzymes.
The development and characterisation of a new biosensor for hydroperoxides is described, which is obtained by combining an oxygen gas diffusion amperometric electrode and two immobilized enzymes (peroxidase and tyrosinase) working in parallel and competing for the same substrate (catechol). The response of the biosensor to several hydroperoxides was investigated (LOD=0.5.10(-4) M for hydrogen peroxide). It was experimentally found that the biosensor is able to respond also to aqueous solutions of ionic peroxides (LOD=0.2.10(-4) M for potassium peroxidisulphate). The biosensor was applied to the determination of the hydrogen peroxide content of pharmaceutical products, i.e. aqueous disinfectant solutions (RSD% < or =0.5; recoveries by standard addition method between 96.0 and 98.5%).
Campanella
L
L
Department of Chemistry, University of Rome La Sapienza, P. le Aldo Moro, 5, 00185 Rome, Italy. mauro.tomassetti@uniroma1.it
Favero
G
G
Giancola
D
D
Tomassetti
M
M
D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D004202:Disinfectants / Q000032:analysis*; D006861:Hydrogen Peroxide / Q000032:analysis*; D014442:Monophenol Monooxygenase / Q000032:analysis*; D009195:Peroxidase / Q000032:analysis*; D019999:Pharmaceutical Solutions / Q000032:analysis; D013997:Time Factors
D004202:Disinfectants; D019999:Pharmaceutical Solutions; D006861:Hydrogen Peroxide; D009195:Peroxidase; D014442:Monophenol Monooxygenase