File Name : figs1.tif

Caption : the effect of surfactant on i%. zen was added to water and 0.5% aeo surfactant solution respectively to make the final concentration 1 ng ml<sup>-1</sup>. then, 80 μl of zen-free and zen-containing water, zen-free and zen-containing surfactant solutions were dropped to the test card. i% was calculated according to the method in section 2.5 of the paper.

File Name : figs2.tif

Caption : standard curve for determination of zen in 2mg ml<sup>-1</sup> of aeo 15 solution. the standard curve was based on bleasdale model and the curve equation is y = (a + bx)<sup>-1/c</sup>, in which a = 0.0154, b = 1.77×10<sup>-3</sup>, c = 2.92, x is the concentration of zen in 2mg ml<sup>-1</sup> of aeo 15 solution, y is ln(t%).

File Name : figs3.tif

Caption : predicted zen concentration by using calculated k value and detected zen concentration by using the colloidal gold immunochromatographic strips in aqueous phase at different w/o ratio.