title: Electrochemical studies on horseradish peroxidase covalently coupled with redox dyes.
abstract: The present study aims at investigating the use of redox dyes as non-diffusional electron mediators in hydrogen peroxide biosensors using horseradish peroxidase (HRP). We observe that the two redox dyes Safranine O and Neutral Red covalently bound to HRP, efficiently mediate electron transfer from the active site of the enzyme to the electrode surface. Dyes bound to the enzyme using a spacer arm diaminohexane further enhance the electron transfer. The enzyme electrodes show a linear response to the concentration of H2O2 up to 500 microM concentration and with a detection limit of around 50 microM. The dyes can be used as coupled mediators to develop a successful electro-optical biosensor.
authors.affiliation: School of Life Sciences, University of Hyderabad, Hyderabad 500046, India.
authors.forename: B S B
authors.initials: BS
authors.lastname: Salomi
authors.forename: Chanchal K
authors.initials: CK
authors.lastname: Mitra
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D004563:Electrochemistry / Q000379:methods*; D006735:Horseradish Peroxidase / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000032:analysis*; D009499:Neutral Red / Q000737:chemistry; D010084:Oxidation-Reduction; D010619:Phenazines / Q000737:chemistry
chemical_list: D010619:Phenazines; D009499:Neutral Red; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase; C009195:safranine T