The synthesized macrocycle L was found to be a smart fluorescent receptor which distinguishable efficiently from various neutral molecules with the functional groups such as the electron donating (X =$CH_3$, N($CH_3$)$_2$ and O$CH_3$) and electron withdrawing groups (X =F and Cl), respectively. In the case of guest molecules containing electron donating groups, the fluorescence of macrocycle L was enhanced in the presence of the guest molecules. On the contrary, in the case of guest molecules containing electron withdrawing groups, it was almost quenched in the presence of those.