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.