An Unprecedented Blueshifted Naphthalimide AIEEgen for Ultrasensitive Detection of 4-Nitroaniline in Water via "Receptor-Free" IFE Mechanism.

The development of a new naphthalene appended naphthalimide derivative (NMI) with aggregation-induced enhanced emission (AIEE) property for the sensitive detection of 4-nitroaniline (4-NA) in aqueous media is presented here. The newly designed naphthalimide AIEEgen has an exceptional blue-shifted condensed state emission that is devoid of any receptor site, accomplished ultrasensitive detection of 4-NA, which is one of the broad-spectrum pesticides that belong to the class III toxic chemical, at parts per billion level (LOD/36 ppb, Ksv =4.1×104  m-1 ) in water with excellent selectivity even in the presence of potentially competing aliphatic and aromatic amines. The reported probe is the first of its kind, demonstrating major advantages of receptor-free inner filter effect (IFE) mechanism for the sensitive detection of 4-NA using an AIEEgenic probe. Excellent sensitivity for 4-NA is also achieved on paper-based test-strip for low-cost on-site detection.