Figure 2.

Logic gate design principles for an AND gate (A), OR gate (B), NAND gate (C), NOR gate (D). The predicted 2D conformations of the RNA aptamers in the presence and absence of individual or both inputs are shown to the right. The rules specified by each gate are shown in truth tables to the left. Normalized fluorescence enhancement of the gates is displayed in the middle. The fluorescence enhancement data are reported with ± standard error of the mean (SEM) bars; measurements have been reproduced from least three repetitive trials.