Abstract: A modified graphite electrode comprising a coating of electrochemically reduced graphene oxide. The modified graphite electrode may be employed in detecting of uric acid. A sensing device comprising the modified graphite electrode and a method of making the modified graphite electrode are described herein.

Abstract: A modified graphite electrode comprising a coating of electrochemically reduced graphene oxide. The modified graphite electrode may be employed in detecting of uric acid. A sensing device comprising the modified graphite electrode and a method of making the modified graphite electrode are described herein.

Abstract: A modified graphite electrode comprising a coating of electrochemically reduced graphene oxide. The modified graphite electrode may be employed in detecting of uric acid. A sensing device comprising the modified graphite electrode and a method of making the modified graphite electrode are described herein.

Abstract: A modified graphite electrode comprising a coating of electrochemically reduced graphene oxide. The modified graphite electrode may be employed in detecting of uric acid. A sensing device comprising the modified graphite electrode and a method of making the modified graphite electrode are described herein.

Abstract: A modified graphite electrode comprising a coating of electrochemically reduced graphene oxide. The modified graphite electrode may be employed in detecting of uric acid. A sensing device comprising the modified graphite electrode and a method of making the modified graphite electrode are described herein.

Abstract: A modified graphite electrode comprising a coating of electrochemically reduced graphene oxide. The modified graphite electrode may be employed in detecting of uric acid. A sensing device comprising the modified graphite electrode and a method of making the modified graphite electrode are described herein.

Abstract: The cathodized gold nanoparticle graphite pencil electrode is a sensitive enzymeless electrochemical glucose sensor based on the cathodization of AuNP-GPE. Cyclic voltammetry shows that advantageously, the cathodized AuNP-GPE is able to oxidize glucose partially at low potential (around ?0.27 V). Fructose and sucrose cannot be oxidized at <0.1 V, thus the glucose oxidation peak at around ?0.27 V is suitable enough for selective detection of glucose in the presence of fructose and sucrose. However, the glucose oxidation peak current at around ?0.27 V is much lower which should be enhanced to obtain low detection limit. The AuNP-GPE cathodization increases the oxidation peak current of glucose at around ?0.27 V. The dynamic range of the sensor is in the range between 0.05 to 5.0 mM of glucose with good linearity (R2=0.999). Almost no interference effect was observed for sensing of glucose in the presence of fructose, sucrose and NaCl.

Abstract: A graphene-modified graphite pencil electrode (GPE) system and a method for detecting 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 graphene comprising wrinkled graphene sheets 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 cell and method for simultaneous electrochemical and EPR measurements, including a disposable assembly, allows for a single device to produce data for both electroanalysis and EPR spectroscopy by generating a Redox reaction to form free radicals. The cell includes first and second hollow tubes, with the second tube being removably insertable into the first hollow tube. The interior of the first tube contains an insulating material, an electro-conductive material, and a wire connector extending from the electro-conductive material and out the first tube. The interior of the second tube contains an electrolytic solution, an analyte, a working electrode, and insulating material surrounding the working electrode. The second tube is inserted into the first tube and a reference electrode is placed into the second tube. The cell is placed within an EPR spectrometer. A potential is applied to the reference electrode to generate the Redox reaction of the analyte.

Abstract: The cathodized gold nanoparticle graphite pencil electrode is a sensitive enzymeless electrochemical glucose sensor based on the cathodization of AuNP-GPE. Cyclic voltammetry shows that advantageously, the cathodized AuNP-GPE is able to oxidize glucose partially at low potential (around ?0.27 V). Fructose and sucrose cannot be oxidized at <0.1 V, thus the glucose oxidation peak at around ?0.27 V is suitable enough for selective detection of glucose in the presence of fructose and sucrose. However, the glucose oxidation peak current at around ?0.27 V is much lower which should be enhanced to obtain low detection limit. The AuNP-GPE cathodization increases the oxidation peak current of glucose at around ?0.27 V. The dynamic range of the sensor is in the range between 0.05 to 5.0 mM of glucose with good linearity (R2=0.999). Almost no interference effect was observed for sensing of glucose in the presence of fructose, sucrose and NaCl.

Abstract: The electroanalytical method for determination of phenols is a method for determining the concentration of phenolic compounds and their chloro-derivatives, on the surface of a glassy carbon electrode (GCE) by cyclic voltammetry (CV) and/or square-wave stripping voltammetry (SWASV) using a redox active polymer film that is formed on the surface of the GCE when the electro-polymerization potential is reached. The electroanalytical method comprises contacting an aqueous sample containing a phenolic compound(s) with an electrode assembly having a working electrode; generating a voltammogram of the analyte by varying an applied accumulation potential or applied potential, and measuring the size of voltammogram peaks corresponding to a redox-active polymeric film that develops at the working electrode at the electro-polymerization potential in order to determine the concentration of the phenolic compound.

Abstract: The pencil graphite electrode modified with porous copper may be used for the detection of 4-nitrophenol (4-NP). The pencil graphite electrode has an outer surface coated with a layer of porous copper. Prior to modification of the pencil graphite electrode, a solution of approximately 0.3 M CuSO4 in an approximately 0.1 M acetate buffer solution (pH 4.8) is prepared. A bare pencil graphite electrode (PGE), extracted from a graphite pencil, is then immersed in this solution. An electrical potential of approximately ?1.2 V is applied for approximately 60 seconds for electrodeposition of copper on the surface of the PGE to form a porous copper layer thereon. The pencil graphite electrode coated with porous copper is then removed from the mixture, washed and dried, and is then ready to be used for the electrochemical detection and quantification of 4-NP.

Abstract: The amperometric nitrate sensor is a graphite pencil electrode (GPE) having an outer surface electrodeposited (coated) with a layer of cobalt, wherein the layer of cobalt is nanostructured. The graphite pencil electrode modified with nano cobalt may be used for detection and sensing nitrate ions (NO3?). The graphite pencil electrode modified with cobalt is prepared by immersing a pencil graphite electrode in an electrodeposition solution that is prepared by mixing CoCl2 in a solution of potassium chloride; and applying an electrical potential of approximately ?1.3 V for 120 seconds across the graphite pencil electrode to form a graphite pencil electrode modified with nano cobalt. The graphite pencil electrode coated with nanostructured cobalt is then removed from the mixture, washed and dried, and is then ready to be used for the amperometric sensing and quantification of nitrate ions.

Abstract: The electroanalytical method for determination of phenols is a method for determining the concentration of phenolic compounds and their chloro-derivatives, on the surface of a glassy carbon electrode (GCE) by cyclic voltammetry (CV) and/or square-wave stripping voltammetry (SWASV) using a redox active polymer film that is formed on the surface of the GCE when the electro-polymerization potential is reached. The electroanalytical method comprises contacting an aqueous sample containing a phenolic compound(s) with an electrode assembly having a working electrode; generating a voltammogram of the analyte by varying an applied accumulation potential or applied potential, and measuring the size of voltammogram peaks corresponding to a redox-active polymeric film that develops at the working electrode at the electro-polymerization potential in order to determine the concentration of the phenolic compound.

Abstract: The cathodized gold nanoparticle graphite pencil electrode is a sensitive enzymeless electrochemical glucose sensor based on the cathodization of AuNP-GPE. Cyclic voltammetry shows that advantageously, the cathodized AuNP-GPE is able to oxidize glucose partially at low potential (around ?0.27 V). Fructose and sucrose cannot be oxidized at <0.1 V, thus the glucose oxidation peak at around ?0.27 V is suitable enough for selective detection of glucose in the presence of fructose and sucrose. However, the glucose oxidation peak current at around ?0.27 V is much lower which should be enhanced to obtain low detection limit. The AuNP-GPE cathodization increases the oxidation peak current of glucose at around ?0.27 V. The dynamic range of the sensor is in the range between 0.05 to 5.0 mM of glucose with good linearity (R2=0.999). Almost no interference effect was observed for sensing of glucose in the presence of fructose, sucrose and NaCl.

Abstract: The cathodized gold nanoparticle graphite pencil electrode is a sensitive enzymeless electrochemical glucose sensor based on the cathodization of AuNP-GPE. Cyclic voltammetry shows that advantageously, the cathodized AuNP-GPE is able to oxidize glucose partially at low potential (around ?0.27 V). Fructose and sucrose cannot be oxidized at <0.1 V, thus the glucose oxidation peak at around ?0.27 V is suitable enough for selective detection of glucose in the presence of fructose and sucrose. However, the glucose oxidation peak current at around ?0.27 V is much lower which should be enhanced to obtain low detection limit. The AuNP-GPE cathodization increases the oxidation peak current of glucose at around ?0.27 V. The dynamic range of the sensor is in the range between 0.05 to 5.0 mM of glucose with good linearity (R2=0.999). Almost no interference effect was observed for sensing of glucose in the presence of fructose, sucrose and NaCl.

Abstract: A cell and method for simultaneous electrochemical and EPR measurements, including a disposable assembly, allows for a single device to produce data for both electroanalysis and EPR spectroscopy by generating a Redox reaction to form free radicals. The cell includes first and second hollow tubes, with the second tube being removably insertable into the first hollow tube. The interior of the first tube contains an insulating material, an electro-conductive material, and a wire connector extending from the electro-conductive material and out the first tube. The interior of the second tube contains an electrolytic solution, an analyte, a working electrode, and insulating material surrounding the working electrode. The second tube is inserted into the first tube and a reference electrode is placed into the second tube. The cell is placed within an EPR spectrometer. A potential is applied to the reference electrode to generate the Redox reaction of the analyte.

Abstract: The disposable palladium nanoparticle-modified graphite pencil electrode (PdNP-GPE) is a graphite pencil electrode having palladium nanoparticles disposed on the surface of the electrode. The electrode is prepared by adding ascorbic acid to an aqueous solution of ammonium tetrachloropalladate(II) [(NH4)2PdCl4] at room temperature to form the palladium nanoparticles (PdNPs), immersing a GPE in the aqueous solution of PdNPs, and heating the solution to about 75° C. to deposit the PdNPs on the GPE. The palladium nanoparticle modified graphite pencil electrode may be used in an electrochemical cell for quantitative analysis of hydrogen peroxide content in an unknown solution.

Abstract: The pencil graphite electrode modified with gold nanoparticles can be used for the detection of hydrazine. The pencil graphite electrode has an outer surface coated with gold nanoparticles. Prior to modification of the pencil graphite electrode, equal volumes of an aqueous solution of ascorbic acid and an aqueous solution of gold(III) chloride are mixed to form a mixture containing gold nanoparticles. A pencil graphite electrode is then immersed in the mixture and is heated at a temperature of about 75° C. to form the pencil graphite electrode coated with gold nanoparticles. The pencil graphite electrode coated with gold nanoparticles is then removed from the mixture, washed and dried, and may then be used for the to electrochemical detection of hydrazine.

Abstract: The disposable palladium nanoparticle-modified graphite pencil electrode (PdNP-GPE) is a graphite pencil electrode having palladium nanoparticles disposed on the surface of the electrode. The electrode is prepared by adding ascorbic acid to an aqueous solution of ammonium tetrachloropalladate(II) [(NH4)2PdCl4] at room temperature to form the palladium nanoparticles (PdNPs), immersing a GPE in the aqueous solution of PdNPs, and heating the solution to about 75° C. to deposit the PdNPs on the GPE. The palladium nanoparticle modified graphite pencil electrode may be used in an electrochemical cell for quantitative analysis of hydrogen peroxide content in an unknown solution.