Fig. 2
(a) RPS current trace obtained for a blank solution (1X PBS, 1 M KCl, pH = 7.4). (b) RPS current traces (time duration = 2 s) obtained for the translocation of 1 nM solutions (with 1X PBS, 1 M KCl) of IgG, streptavidin, cytochrome C, and myoglobin. Downward spikes in the current traces represent individual translocation events for each protein. The molecules were translocated through two in-plane nanopores with an effective diameter of ~ 10 nm. Refer to Table 1 for detailed information on the four proteins. All traces, including the blank, were digitally low pass filtered at 10 kHz and acquired under a driving voltage of 1 V. Histograms displaying the distribution of normalized peak amplitude (ΔI/I0) (c), time-of-flight (ToF) (d), and dwell time, tD (e) values derived from resistive pulse recordings of IgG, streptavidin, cytochrome C, and myoglobin. Numbers in the histograms represent the median ± interquartile range. RPS current traces were acquired for a duration of 2 s and obtained from the translocation of 1 nM solutions (with 1X PBS, 1 M KCl) of each protein. Results of a one-way analysis of variance (ANOVA) and Tukey’s multiple comparisons test for each RPS event characteristic of IgG, streptavidin, cytochrome C and myoglobin; ΔI/I0 (f), tD (g) and ToF (h). Results from three different translocation experiments (n = 3) were considered for the analysis (f). For ANOVA and Tukey’s multiple comparisons tests: The overall p values for the ΔI/I0, tD and ToF were 0.0003, 0.0002 and 0.0004, respectively. For ΔI/I0, *p = 0.0151, **p = 0.0011, ***p = 0.0002, ns (not significant) = 0.2036. For tD, *p = 0.0496, **p = 0.0065, ***p = 0.0007, ns = 0.2676. For ToF, *p = 0.0381, **p = 0.0091, ***p = 0.0002, ns = 0.9664.
