Figure 4. HepG2 cell viability study. The hepatocytes viability was assessed by using live/dead assay over a period of 7 days. (A) Control is HepG2 cells not exposed to electrodes (B) Test is HepG2 cells exposed to Nafion/MWCNT/GOx coated electrodes.
HepG2 cells are human nontumorigenic hepatoma cells that are most commonly used for drug metabolism and toxicity studies (39). Before using the designed glucose sensor for the LOC platform, we used the glucose sensor for 2D cell culture to evaluate the cytotoxicity of the biosensor. We cultured HepG2 cells in 2D for evaluation. A live/dead experiment was conducted using a solution containing D-PBS, calcein-AM, and Ethd-1. The living cells were dyed green due to calcein-AM, and the dead cells were dyed red due to Ethd-1. As can be seen from Fig. 4, for both the control well cultured under standard cell culture conditions and the test well coated with Nafion/MWCNT/GOx, very few red cells were found, and there was no difference In the cell survival rate in the live/dead assay.