Electrochemical Detection of Glutathione Based on Inkjet-Printed Graphene Modified Screen Printed Carbon Paste Electrode

摘要

In this work, we report a simple and effective electrochemical detection of glutathione (GSH) based on inkjet-printed graphene-poly(3,4-ethylenedioxythiophene) poly(styrene-sulfonate) (GP-PEDOT:PSS) modified screen printed carbon paste electrode (SPCE) using linear sweep voltammetry (LSV). The GP-PEDOT:PSS electrode demonstrates excellent GSH detection performances with LSV response and PEDOT:PSS electrode 141.13 and 38.46 times better than those of unmodified SPCE and PEDOT:PSS modified SPCE, respectively. Additionally, the current response of GP-PEDOT:PSS electrode is linearly proportional to the GSH concentration over a wide dynamic range from 0.31 to 921.96 mg/l (1-3000 μM) in 0.1 M PB solution (pH 8.0) with a moderate sensitivity of 0.0832 μA/mg/l (0.026 μA/μM), a low detection limit (3S/N) of 0.42 mg/l (1.35 μM) and a moderate limit of quantification (10S/N) of 2.56 mg/l (8.30 μM). The diffusion coefficient (D) and the electron transfer coefficient (α) of GSH are 5.01 × 10~(-4) cm~2 s~(-1) and 0.66, respectively. Some pharmaceutical products including Nutri Master E-Zywite, Watsons Premate and Glutathione Nutrakal have successfully been analyzed directly with low matrices' interference. Therefore, the inkjet-printed GP-PEDOT:PSS electrode is a promising candidate for an electrochemical analysis of GSH.