Abstract: An electrode for use in a electrochemical sensor comprises carbon modified with a chemically sensitive redox-active compound, excluding an electrode based on carbon having derivatized thereon two redox-active species wherein at least one of said species is selected from anthraquinone, phenanthrenequinone and N,N?-diphenyl-p-phenylenediamine (DPPD). The invention further provides a pH sensor comprising: a working electrode comprising carbon modified with a chemically sensitive redox active material; and a counter electrode, wherein the ratio of the surface area of the working electrode to the surface area of the counter electrode is from 1:10 to 10:1. Also provided is a pH sensor comprising: a working electrode comprising carbon modified with a chemically sensitive redox active material, and a counter electrode, wherein the area of the working electrode is from 500 ?m2 to 0.1 m2. The uses of these electrodes and sensors are also described.

Abstract: An electrode for use in a electrochemical sensor comprises carbon modified with a chemically sensitive redox-active compound, excluding an electrode based on carbon having derivatised thereron two redox-active species wherein at least one of said species is selected from anthraquinone, phenanthrenequinone and N,N?-diphenyl-p-phenylenediamine (DPPD). The invention further provides a pH sensor comprising: a working electrode comprising carbon modified with a chemically sensitive redox active material; and a counter electrode, wherein the ratio of the surface area of the working electrode to the surface area of the counter electrode is from 1:10 to 10:1. Also provided is a pH sensor comprising: a working electrode comprising carbon modified with a chemically sensitive redox active material, and a counter electrode, wherein the area of the working electrode is from 500 ?m2 to 0.1 m2. The uses of these electrodes and sensors are also described.

Abstract: An electrode for use in a electrochemical sensor comprises carbon modified with a chemically sensitive redox-active compound, excluding an electrode based on carbon having derivatized thereron two redox-active species wherein at least one of said species is selected from anthraquinone, phenanthrenequinone and N,N?-diphenyl-p-phenylenediamine (DPPD). The invention further provides a pH sensor comprising: a working electrode comprising carbon modified with a chemically sensitive redox active material; and a counter electrode, wherein the ratio of the surface area of the working electrode to the surface area of the counter electrode is from 1:10 to 10:1. Also provided is a pH sensor comprising: a working electrode comprising carbon modified with a chemically sensitive redox active material, and a counter electrode, wherein the area of the working electrode is from 500 ?m2 to 0.1 m2. The uses of these electrodes and sensors are also described.

Abstract: An electrode for use in a electrochemical sensor comprises carbon modified with a chemically sensitive redox-active compound, excluding an electrode based on carbon having derivatised thereron two redox-active species wherein at least one of said species is selected from anthraquinone, phenanthrenequinone and N,N?-diphenyl-p-phenylenediamine (DPPD). The invention further provides a pH sensor comprising: a working electrode comprising carbon modified with a chemically sensitive redox active material; and a counter electrode, wherein the ratio of the surface area of the working electrode to the surface area of the counter electrode is from 1:10 to 10:1. Also provided is a pH sensor comprising: a working electrode comprising carbon modified with a chemically sensitive redox active material, and a counter electrode, wherein the area of the working electrode is from 500 ?m2 to 0.1 m2. The uses of these electrodes and sensors are also described.

Abstract: An electrode for use in a electrochemical sensor comprises carbon modified with a chemically sensitive redox-active compound, excluding an electrode based on carbon having derivatised thereron two redox-active species wherein at least one of said species is selected from anthraquinone, phenanthrenequinone and N,N?-diphenyl-p-phenylenediamine (DPPD). The invention further provides a pH sensor comprising: a working electrode comprising carbon modified with a chemically sensitive redox active material; and a counter electrode, wherein the ratio of the surface area of the working electrode to the surface area of the counter electrode is from 1:10 to 10:1. Also provided is a pH sensor comprising: a working electrode comprising carbon modified with a chemically sensitive redox active material, and a counter electrode, wherein the area of the working electrode is from 500 ?m2 to 0.1 m2. The uses of these electrodes and sensors are also described.

Abstract: An electrode for use in a electrochemical sensor comprises carbon modified with a chemically sensitive redox-active compound, excluding an electrode based on carbon having derivatised thereron two redox-active species wherein at least one of said species is selected from anthraquinone, phenanthrenequinone and N,N?-diphenyl-p-phenylenediamine (DPPD). The invention further provides a pH sensor comprising: a working electrode comprising carbon modified with a chemically sensitive redox active material; and a counter electrode, wherein the ratio of the surface area of the working electrode to the surface area of the counter electrode is from 1:10 to 10:1. Also provided is a pH sensor comprising: a working electrode comprising carbon modified with a chemically sensitive redox active material, and a counter electrode, wherein the area of the working electrode is from 500 ?m2 to 0.1 m2. The uses of these electrodes and sensors are also described.

Abstract: An electro-chemical sensor is described having two molecular redox systems sensitive to the same species and having an detector to detect relative shifts in the voltammograms of the two redox systems.

Abstract: Derivatised carbon is disclosed in which an amino acid or a derivative thereof is attached to the carbon. Derivatised carbon may be useful in the detection and removal of metal ions from liquid media.