Background: GSH has a relevant role in human metabolism as an indicator of disease risks. An amperometric sensor for glutathione (GSH) determination is described as an alternative method featuring simple construction procedure and short time analysis. Method: The developed sensor was used to determine glutathione at low potential using a TTF-TCNQ complex. Results: The sensor exhibits a linear response range from 5 to 340 mu mol/l under applied potential of 200 mV vs. SCE. The sensitivity and detection limit were 90.1 mu A l/mmol cm(2) and 0.3 mu mol/l, respectively. Conclusion: When the sensor was tested in hemolysed erythrocyte samples for GSH determination, a good correlation in results was observed between the sensor and the spectrophotometric method. The sensor showed recovery values between 98% and 102%. (c) 2006 Elsevier B.V All rights reserved.