Abstract: A method of using a graphite electrode to measure a concentration of glucose or methionine from a biological sample is described. A mechanical pencil lead may be used as the graphite electrode, and the biological sample may come from a patient's serum. The glucose or methionine may produce a peak current response within a range of 0.4-0.8 V when the sample is subjected to linear scan voltammetry.

Abstract: A method of using a graphite electrode to measure a concentration of glucose or methionine from a biological sample is described. A mechanical pencil lead may be used, as the graphite electrode, and the biological sample may come from a patient's serum. The glucose or methionine may produce a peak current response within a range of 0.4-0.8 V when the sample is subjected to linear scan voltammetry.

Abstract: A graphene-modified graphite pencil electrode (GPE) system and a method for simultaneous detection of multiple anylates such as dopamine, uric acid, and L-tyrosine in a solution. The electrode system includes a graphene-modified graphite pencil working electrode comprising a graphite pencil base electrode and a layer of three dimensional nanostructured multiwall network forming concave shape structures on the surface of the graphite pencil base electrode, a counter electrode, and a reference electrode. The method comprises contacting the solution with the graphene-modified GPE system and conducting voltammetry, preferably square wave voltammetry, to detect the L-tyrosine concentration in the solution.

Abstract: A method of using a graphite electrode to measure a concentration of glucose or methionine from a biological sample is described. A mechanical pencil lead may be used, as the graphite electrode, and the biological sample may come from a patient's serum. The glucose or methionine may produce a peak current response within a range of 0.4-0.8 V when the sample is subjected to linear scan voltammetry.

Abstract: A method of determining a concentration of phenol and/or a phenol derivative in a first solution. The method includes (a) subjecting a graphite pencil electrode system comprising a graphite pencil working electrode, a counter electrode, and a reference electrode to cyclic voltammetry in a second solution such that a surface of the graphite pencil working electrode is charged by the cyclic voltammetry to form a charged surface, (b) contacting the charged surface of the graphite pencil working electrode with the first solution for sufficient time to electropolymerize the phenol and/or the phenol derivative on the charged surface in open circuit fashion, and (c) determining the concentration of the phenol and/or the phenol derivative in the first solution, wherein the amount of the electropolymerized phenol and/or the electropolymerized phenol derivative formed on the charged surface correlates with the concentration of the phenol and/or the phenol derivative in the first solution.

Abstract: A method of determining a concentration of phenol and/or a phenol derivative in a first solution. The method includes (a) subjecting a graphite pencil electrode system comprising a graphite pencil working electrode, a counter electrode, and a reference electrode to cyclic voltammetry in a second solution such that a surface of the graphite pencil working electrode is charged by the cyclic voltammetry to form a charged surface, (b) contacting the charged surface of the graphite pencil working electrode with the first solution for sufficient time to electropolymerize the phenol and/or the phenol derivative on the charged surface in open circuit fashion, and (c) determining the concentration of the phenol and/or the phenol derivative in the first solution, wherein the amount of the electropolymerized phenol and/or the electropolymerized phenol derivative formed on the charged surface correlates with the concentration of the phenol and/or the phenol derivative in the first solution.

Abstract: A method of determining a concentration of phenol and/or a phenol derivative in a first solution. The method includes (a) subjecting a graphite pencil electrode system comprising a graphite pencil working electrode, a counter electrode, and a reference electrode to cyclic voltammetry in a second solution such that a surface of the graphite pencil working electrode is charged by the cyclic voltammetry to form a charged surface, (b) contacting the charged surface of the graphite pencil working electrode with the first solution for sufficient time to electropolymerize the phenol and/or the phenol derivative on the charged surface in open circuit fashion, and (c) determining the concentration of the phenol and/or the phenol derivative in the first solution, wherein the amount of the electropolymerized phenol and/or the electropolymerized phenol derivative formed on the charged surface correlates with the concentration of the phenol and/or the phenol derivative in the first solution.

Abstract: A method of determining a concentration of phenol and/or a phenol derivative in a first solution. The method includes (a) subjecting a graphite pencil electrode system comprising a graphite pencil working electrode, a counter electrode, and a reference electrode to cyclic voltammetry in a second solution such that a surface of the graphite pencil working electrode is charged by the cyclic voltammetry to form a charged surface, (b) contacting the charged surface of the graphite pencil working electrode with the first solution for sufficient time to electropolymerize the phenol and/or the phenol derivative on the charged surface in open circuit fashion, and (c) determining the concentration of the phenol and/or the phenol derivative in the first solution, wherein the amount of the electropolymerized phenol and/or the electropolymerized phenol derivative formed on the charged surface correlates with the concentration of the phenol and/or the phenol derivative in the first solution.

Abstract: A method of determining a concentration of phenol and/or a phenol derivative in a first solution. The method includes (a) subjecting a graphite pencil electrode system comprising a graphite pencil working electrode, a counter electrode, and a reference electrode to cyclic voltammetry in a second solution such that a surface of the graphite pencil working electrode is charged by the cyclic voltammetry to form a charged surface, (b) contacting the charged surface of the graphite pencil working electrode with the first solution for sufficient time to electropolymerize the phenol and/or the phenol derivative on the charged surface in open circuit fashion, and (c) determining the concentration of the phenol and/or the phenol derivative in the first solution, wherein the amount of the electropolymerized phenol and/or the electropolymerized phenol derivative formed on the charged surface correlates with the concentration of the phenol and/or the phenol derivative in the first solution.

Abstract: A method of determining a concentration of phenol and/or a phenol derivative in a first solution. The method includes (a) subjecting a graphite pencil electrode system comprising a graphite pencil working electrode, a counter electrode, and a reference electrode to cyclic voltammetry in a second solution such that a surface of the graphite pencil working electrode is charged by the cyclic voltammetry to form a charged surface, (b) contacting the charged surface of the graphite pencil working electrode with the first solution for sufficient time to electropolymerize the phenol and/or the phenol derivative on the charged surface in open circuit fashion, and (c) determining the concentration of the phenol and/or the phenol derivative in the first solution, wherein the amount of the electropolymerized phenol and/or the electropolymerized phenol derivative formed on the charged surface correlates with the concentration of the phenol and/or the phenol derivative in the first solution.