An AIE self-assembly system (APNP) was constructed based on 2, 9-diamino- 1,10-phenanthroline (APhen). APNP could form fluorescent organogels in some solvents along with the formation of microbelt and microrod. The self-assembly behaviors of APNP in different solvents were studied by multiple technologies. The formation of the gel mainly benefited from hydrogen bonding. Even APhen as basic skeleton possessed the sizably conjugated structure, π-π stacking interaction between them was effectively prohibited due to the large steric hindrance at the terminal, which was successfully induced the transformation from ACQ to AIE. Solution APNP possessed highly selective and ultrafast detection of Hg2+ with a low limit of detection (LOD) of 1.57 nM. Gel APNP in THF/H 2 O (v/v, 5/1) also exhibited selective response to Hg2+ by showing multimode signal expression including colour, gel state and emission. APNP could detect volatile acids in solution, gel and film states via protonation of the 1, 10-phenanthroline group. Especially for gaseous TFA, film APNP could rapidly detect TFA gases with a very low LOD of 7.95 ppb within 0.5 s. The present study will provide a new way to achieve AIE fluorescent materials from ACQ materials. [Display omitted] • The transition of ACQ-AIE is realized by suppressing intermolecular π-π stacking. • AIE gel sensor is synthesized for sensing Hg2+ and volatile acids in multi-modes. • Film APNP is constructed as anti-counterfeiting material based on emission change. [ABSTRACT FROM AUTHOR]