Sensitive detection of MCF-7 cells based on poly calcein modified electrode and its applied in cytotoxicity assay

It is highly desirable to develop cost-effective and sensitive cell sensors to evaluate cytotoxicity of anticancer drugs. For the first time, a simple and cheap poly calcein modified electrode(PCA/GCE) prepared by one-step in situ polymerization was applied for study the electrochemical behavior of MCF-7 cells. Since the negative charge and unique properties of calcein can increase sensitivity, the resulting linear scanning of the MCF-7 cells on electrode exhibited two anodic peak that was ascribe to xanthine/guanine(signal) and hypoxanthine/adenine (signal). Meanwhile, the nonlinear exponent relationships between peak current (I_pa) and cell concentration (C) in the wide concentration range were firstly demonstrated. Two independent index equation based on two signal were I_pa (signal) = 7.458 - 6.415e (-C/52380) (R² = 0.986) and I_pa (signal) = 4.023 - 3.773e (-C/228700) (R² = 0.984) with the low detection limit of 3000 cells mL^-1, respectively. Electrochemical responses based on two signals of MCF-7 cells was applied to evaluate cytotoxicity effect of cyclophosphamide (CTX) on MCF-7 cells, the result was in good agreement with that of MTT method. This proposed method could be used to evaluate cytotoxicity of drug.