Sensitivity of Ebeacon system for target DNA detection.
(a) Calibration
curve of the sensing system for target DNA. The curve was plotted
with the initial rate of fluorescence enhancement vs DNA concentration.
From bottom to top: 0 pM, 5 pM, 10 pM, 20 pM, 50 pM, 100 pM, 200 pM,
500 pM, 1 nM, 2 nM, 5 nM, and 10 nM. The inset shows the responses
at low DNA concentrations. Error bars show the standard deviations
of measurements taken from three independent experiments. (b) Fluorescence
kinetics monitoring conversion of entropy beacon system to the waste
strand and release of the reporter strand. No release is discernible
in the absence of the target strand (control). However, rapid release
of the reporter sequence is observed upon introducing 10 nM target
strand. Substoichiometric target strand concentrations demonstrate
turnover, with the conversion rate decreasing monotonically with target
concentration.