Screen-printable surfactant-induced sol-gel graphite composites for electrochemical sensors

A novel procedure to prepare sol-gel graphite composite electrodes is presented. This procedure uses the surfactant bis(2-ethylhexyl) sulfosuccinate (AOT) and eliminates the need for a cosolvent, an acidic catalyst, a cellulose binder and thermal curing. Cobalt phthalocyanine (CoPC), diphenylthiocarbazone (DPT) and glucose oxidase (GOx)/ferrocene (Fc) were encapsulated during the surface preparation to study the utility of these composites as catalytic surfaces and biochemical sensors. The glucose sensor has a useful working range up to 30 mM with a 10 s response time. The DPT-modified electrode has been applied for lead determination based on a complexing/voltammetric strategy. The CoPC modified surface was catalytically active for reduced glutathione (GSH) reducing the onset potential for its oxidation by 400 mV. Fabrication of screen-printed electrodes by this method proved to be a simple approach for electroanalytical applications in aqueous and nonaqueous solvents. (C) 1998 Elsevier Science S.A. All rights reserved.