Figure 3

Analytical sensitivity improvement of LFA by different lengths of sponge. The detection limit of unmodified LFA is 1 nM (A), 3 mm of sponge length is 0.5 nM (B), 5 mm of sponge length is 0.5 nM (C) and 7 mm of sponge length is 0.25 nM (D). (E) The optical density of LFA test line under different lengths of sponge. (F) The wicking distance on the NC membrane with time at different sponge shunt lengths. (G) The relationship between the experimental data and simulation data. Three replicates were performed for the optimization experiments for high concentrations in the range of 2.5–50 nM (N = 3), while eight replicates were performed for lower concentrations in the range of 0.05–1 nM (N = 8).