Quantifying Reduced Glutathione by Square-wave VoltammetryMarcos Vergilio Corrêa-da-Silva1,2, Acácio Antonio Pigoso1, Beatriz Felicio Ribeiro1, Laís Oliveira Barbosa1, Claudio Aparecido Rosado Miloch1 and Armindo Antonio Alves1,2,3*
- *Corresponding Author:
- Armindo Antonio Alves
Graduate Program in Biomedical Sciences
Herminio Ometto University Center
Herminio Ometto-Uniararas, Brazil
E-mail: [email protected]
Received Date: February 19, 2013; Accepted Date: March 27, 2013; Published Date: March 29, 2013
Citation: Corrêa-da-Silva MV, Pigoso AA, Ribeiro BF, Barbosa LO, Rosado Miloch CA, et al. (2013) Quantifying Reduced Glutathione by Square-wave Voltammetry. J Biosens Bioelectron 4:133. doi: 10.4172/2155-6210.1000133
Copyright: © 2013 Corrêa-da-Silva MV, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
This study examines the use of square wave voltammetry (SWV) to quantify reduced glutathione (GSH) dissolved in phosphate buffer (pH 7.5) using a static mercury drop electrode (working), Ag/AgCl electrode (standard) and a platinum wire (auxiliary). The applied voltage ranged from -0.7 to -0.2 V. Increasing concentrations of GSH (13-188μmol/L) correlated with the voltammogram peak area (R2=0.99) and with the current at peak potential (Ip) (R=0.99). The reaction of GSH with diamide was monitored for validation of the method. Addition of increasing concentrations
of diamide (13.3-50.8 μmol/L) to a fixed concentration of GSH (120 μmol/L) decreased the Ip, and the results obtained presented a relative deviation (RD) ≤ 14.5% (compared with expected concentrations by stoichiometry) for GSH concentrations above 33.8 μmol/L, whereas the spectrophotometric method (Elman’s reagent) presented RD ≤ 25.6%. These data indicate that SWV method is more accurate and presented equal precision (SD<8%) as compared to the commonly used spectrophotometric method. This method seems suitable for measuring GSH concentrations at room temperature and pH 7.5 (near biological conditions). Other advantages of this method that make it highly desirable for rapid diagnostic purposes include low cost, simplicity, sensitivity, rapid response and no prior sample preparation.