Voltammetric Sensor for the Determination of Diabetes Rrisk Biomarkers, 8-Hydroxydeoxyguanosine and 8-Hydroxyguanine
Authors: Goyal Rajendra N , Gupta Pankaj 
Published: February 2020

Diabetes is a serious and one of the growing health care problem worldwide and is associated with the oxidative DNA damage, resulting increased level of metabolites such as 8-hydroxydeoxyguanosine (8-OHdeGuo) and 8 – hydroxyguanine (8-OHGua) in biological fluids. In the present studies efforts have been made for the development of a simple, fast and reliable method for the analysis of these compounds formed by the oxidative DNA damage in body fluids. An electrochemical study at gold nanoparticles attached single walled carbon nanotubes modified pyrolytic graphite has been employed for studying the oxidation of these compounds with an aim to develop a method for the self diagnosis of diabetes. The modified sensor was characterized by using FE-SEM, AFM and Impedance studies and the effective surface area of the modified electrode was found to enhance significantly in comparison to the bare surface. The oxidation of both the compounds occurred in a pH dependent process and the electrode reaction followed adsorption controlled pathway. The linear calibration curve for 8-OHGua is obtained over the concentration range 0.01 – 10.0 nM and detection limit and sensitivity of 5.0 (± 0.1) pM and 4.9 (± 0.1) μA nM−1, are observed respectively.Similarly 8-OHdeGuo exhibited linear dynamic range of 0.005 – 20 nM and a detection limit of 1.0 (± 0.1) pM was observed. The method has been found selective and successfully used for the determination of these compounds in urine samples of diabetic patients. Diabetes is a serious and one of the growing health care problem worldwide and is associated with the oxidative DNA damage, resulting increased level of metabolites such as 8-hydroxydeoxyguanosine (8-OHdeGuo) and 8 – hydroxyguanine (8-OHGua) in biological fluids. In the present studies efforts have been made for the development of a simple, fast and reliable method for the analysis of these compounds formed by the oxidative DNA damage in body fluids. An electrochemical study at gold nanoparticles attached single walled carbon nanotubes modified pyrolytic graphite has been employed for studying the oxidation of these compounds with an aim to develop a method for the self diagnosis of diabetes. The modified sensor was characterized by using FE-SEM, AFM and Impedance studies and the effective surface area of the modified electrode was found to enhance significantly in comparison to the bare surface. The oxidation of both the compounds occurred in a pH dependent process and the electrode reaction followed adsorption controlled pathway. The linear calibration curve for 8-OHGua is obtained over the concentration range 0.01 – 10.0 nM and detection limit and sensitivity of 5.0 (± 0.1) pM and 4.9 (± 0.1) μA nM−1, are observed respectively.Similarly 8-OHdeGuo exhibited linear dynamic range of 0.005 – 20 nM and a detection limit of 1.0 (± 0.1) pM was observed. The method has been found selective and successfully used for the determination of these compounds in urine samples of diabetic patients.