An electrochemical method for evaluation the cytotoxicity of fluorene on reduced graphene oxide quantum dots modified electrode

Fluorene was one of the priority controlled polycyclic aromatic hydrocarbons (PAHs) and distributed abundantly in the environment, which has a great harmful on human body. It was very important to detect the cytotoxicity of fluorene with a rapid and accurate method. In this present work, a simple and ultrasensitive electrochemical biosensor was developed by electrodeposition of reduced graphene oxide quantum dots (RGOQDs) on glassy carbon electrode (GCE) for the first time. The electrochemical behaviors of uric acid (UA), xanthine (X) and guanine (G) were studied on RGOQDs/GCE by differential pulse voltammetry (DPV) with a limit of detection of 0.024   μM, respectively. Then the electrochemical biosensor was used to evaluate the cytotoxicity of fluorene for MCF-7 cells based on the variation of G/X in MCF-7 cells solution. The result showed that fluorene exposed to MCF-7 cells at the concentration range of 0–0.05   mM could promote cell proliferation, the concentration above 0.05   mM exhibited inhibitory effect, which was verified by methyl-thiazolyl-tetrazolium (MTT) assay. The electrochemical biosensor based on RGOQDs/GCE could be used not only for evaluation the cytotoxicity of PAHs, but also for detection the physiological process related to intracellular purine nucleotide metabolism.