Fig. 1: c-PEDOT:PSS film characterization.

a A photograph of the c-PEDOT:PSS-PET substrate immersed in water. b Plots of the normalized thickness (upper) and optical transmittance of the c-PEDOT:PSS films (lower) with respect to the duration of immersion in DI water and phosphate-buffered saline (PBS). d₀ and T₀ denote the initial film thickness and transmittance, respectively, at day 0 before water immersion. c X-ray diffractograms of pristine PEDOT:PSS and various c-PEDOT:PSS films (as fabricated, immersed in DI water and PBS for 5 days). d Plots of the electrical conductivities of c-PEDOT:PSS films with respect to the duration of immersion in DI water and PBS. e Statistical distributions of the cell viability on PET, PEDOT:PSS, chemically cross-linked PEDOT:PSS, and c-PEDOT:PSS on PET after 1- and 3-day cultures. NIH-3T3 cells were stained with calcein AM and Hoechst 33342 to identify the viable cells and total cell nuclei, respectively. The data are presented as the mean ± s.e.m., and their variances were evaluated by a two-tailed t-test (n.s: not significant, *P < 0.05, **P < 0.01, ***P < 0.001, N = 12)