Abstract: A method for potentiometric detection of hydrogen peroxide including providing an electrolytic cell having a working electrode and a reference electrode. The working electrode is composed of a hydrogen peroxide sensitive material and also is employed as a support for an oxidase enzyme. Introducing a hydrogen peroxide releasing substance into the cell and releasing the hydrogen peroxide by effecting interaction with the enzyme. Developing in said cell an electrical potential which is a function of the concentration of the hydrogen peroxide and measuring the electrical potential of the cell. The method may be employed as a quantitative glucose detector by employing as the enzyme or enzymes glucose oxidase with or without catalase.Apparatus for potentiometric determination of hydrogen peroxide includes a cell containing an electrolyte, a working electrode and a reference electrode. An electrometer is operatively associated with the electrodes.

Abstract: Phenol or a phenol related compound is detected in an electrochemical cell comprising a cathodic compartment containing a cathode in an electrolyte solution containing ferrocyanide ion and an anodic compartment containing an anode formed by coating a gel containing a phenol or phenol related compound oxidizing enzyme onto the conductive substrate of said anode immersed into an electrolyte solution containing ferrocyanide ion into which pure oxygen is passed; means for maintaining a conductive relationship between anodic and cathodic compartments; and means connected to said anode and cathode for measuring the potential of the oxidation of said phenol or related compound.