Amperometric determination of choline released from rat submandibular gland acinar cells using a choline oxidase biosensor.

A choline (CHO) biosensor based on the determination of H(2)O(2) generated at the electrode surface by the enzyme choline oxidase (CHOx) was developed. The biosensor consisted of CHOx retained onto a horseradish peroxidase (HRP) immobilized solid carbon paste electrode (sCPE). The HRPsCPE contained the molecule phenothiazine as redox mediator and CHOx was physically retained on the electrode surface using a dialysis membrane.

Hydrogen peroxide sensitive amperometric biosensor based on horseradish peroxidase entrapped in a polypyrrole electrode.

The enzyme horseradish peroxidase (HRP) has been entrapped in situ by electropolymerization of pyrrole onto a platinum electrode. The latter was previously coated by a polypyrrole layer for better adhesion of the biocatalyst film and in order to avoid the enzyme folding onto the Pt electrode. The biosensor allowed the determination of hydrogen peroxide in the concentration range comprised between 4.

Reagentless enzyme electrode based on phenothiazine mediation of horseradish peroxidase for subnanomolar hydrogen peroxide determination.

The development and characterization of a highly sensitive enzyme immobilized carbon based electrode for the determination of subnanomolar concentrations of hydrogen peroxide in aqueous samples is described. The biosensor consists of horseradish peroxidase (HRP) immobilized in solid carbon paste along with a suitable redox mediator. The latter allows the acceleration of the electroreduction of HRP in the presence of hydrogen peroxide.