It is highly desirable to develop simple and rapid method to detect cancer cells. In this case, a simple method for electrochemical detecting cell numbers based cytosensor was investigated. Thioctic acid (TA) monolayer, assembled on a high conductive Au/ITO substrate to stable immobilized of Arg-Gly-Asp-Ser tetrapeptide (RGDS) by chemical bonding, was first used for construction of electrochemical cytosensor. Moreover the cytotoxicity assay also showed no cytotoxicity of TA modified electrode. The proposed cytosensor showed good performance for detection of cancer cells with a broad detection range of 3.0 x 10(2) to 1.0 x 10(7) cells/mL, and a low detection limit of 300 cells/mL. The results were obtained that can be attributed to the combination of the advantages of high conductive and biocompatible property of the modified electrode we suggested. This work demonstrated a simple strategy to prepare an electrochemical cytosensor with the property of low cost, good biocompatible, broad detection range, low detection limit, good repeatability which may have potential large-scale application for improving cancer diagnosis and treatment. (C) 2014 Elsevier Ltd. All rights reserved.