These two pictures are drew with the same parameters coming from related literature.Both figers point out that the output signal(GFP,yellow line) will form a pulse immediately after the input signal alters.
Figure 1: This figer shows the concentration variation of chemical moleculars when the input signal is at positive edge when t=0.
Figure 2: This figer shows the concentration variation of chemical moleculars when the input signal is at negative edge when t=0.