A new [3 + 3] trimeric macrocycle, based on tetraphenylethylene having an aggregation-induced emission effect, could form a interdigitation molecular cage with a big void by host-guest interactions. The cage could accommodate two TNT molecules and detect TNT at the 1.7 fg level per mL of air. Moreover, the cage could give permanent pores that had a BET surface area of 347 m2/g and could adsorb 7.8 wt % CO2 with high CO2/N2 selectivity up to 32 (273 K, 1 bar).