Figure 4: Comparison of fluorescence signaling by various chromophores on the (a) ATP-, (b) theophylline- and (c) thrombin-binding aptamers. The % decrease of fluorescence (%) is calculated from the difference in fluorescence intensities of the chromophores (25 nM) in presence of 10 nM aptamer with and without 10 nM target. Data presented in plot is the mean of three measurements and error bars indicate standard deviations.