ItemArticle

An ESIPT/AIE active Schiff Base for the selective detection of Picric acid, Ammonia, and its potential applications in anticounterfeiting and latent fingerprinting

Title
An ESIPT/AIE active Schiff Base for the selective detection of Picric acid, Ammonia, and its potential applications in anticounterfeiting and latent fingerprinting
Creator
Varghese, Nikita; KP, Chaithra; John, Varsha Lisa; Fasila, P.M.; Nair, Yamuna; Vinod, T.P.; Davis, Maria; Johar, Cerin
Description
A novel ESIPT/AIE-active Schiff base fluorophore, N?1,N?6-bis((Z)-2,4-dihydroxybenzylidene)adipohydrazide (ADHB), has been designed and synthesized. ADHB exhibits remarkable selectivity and sensitivity towards picric acid in aqueous phase, as well as ammonia in both aqueous and solid phases, with LOD values of 55.5 nM and 88.7 nM respectively, facilitating its efficacy in real sample analysis. While exhibiting notable luminescence in polar solvents (? = 0.15 %), ADHB displays pronounced fluorescence enhancement in the solid state (??? = 320 nm) due to aggregation-induced emission (AIE). The molecular skeleton of ADHB incorporates two potential excited-state intramolecular proton transfer (ESIPT) active sites that exhibit distinctive, reversible halochromic properties in the solid state. The adaptability of this Schiff base as a multi-responsive fluorescent material was explored by the fabrication of a blue-emitting polyvinyl alcohol (PVA) composite film and paper-based test strips. The detection limits agree with the amount of contaminants that the U.S. Environmental Protection Agency (EPA) allows in drinking water. The sensing mechanism was elucidated through comprehensive DFT studies, NMR titration studies and Job's plot analysis. The tunable photophysical properties of this AIE-active probe facilitates practical applications in anti-counterfeiting and latent fingerprint visualization, highlighting its significance in forensic science and security authentication. These findings establish ADHB as a fluorescent platform for the sensitive detection and continuous monitoring of hazardous compounds in environmental systems. 2025 Elsevier B.V.
Source
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy;Volume;346;Issue;;Article No.;126910;
Date
01-01-2026
Publisher
Elsevier B.V.
Subject
Aggregation induced emission (AIE); Anticounterfeiting; Excited state intramolecular proton transfer (ESIPT); Fluorescence switching; Latent fingerprinting (LFP); Schiff base
Coverage
Varghese N., Department of Chemistry, Christ University, Bangalore, 560029, India; KP C., Department of Chemistry, Christ University, Bangalore, 560029, India; John V.L., Department of Chemistry, Christ University, Bangalore, 560029, India; Fasila P.M., Department of Chemistry, Sir Syed College, Taliparamba, Kerala, Kannur, 670142, India; Nair Y., Department of Chemistry, Christ University, Bangalore, 560029, India; Vinod T.P., Department of Chemistry, Christ University, Bangalore, 560029, India; Davis M., Department of Chemistry, Christ University, Bangalore, 560029, India; Johar C., Department of Chemistry, Christ University, Bangalore, 560029, India
Rights
Restricted Access; Hardcopy may be available in the library
Relation
ISSN: 13861425; CODEN: SAMCA
Format
online
Language
English
Type
Article

Citation

Varghese, Nikita; KP, Chaithra; John, Varsha Lisa; Fasila, P.M.; Nair, Yamuna; Vinod, T.P.; Davis, Maria; Johar, Cerin, “An ESIPT/AIE active Schiff Base for the selective detection of Picric acid, Ammonia, and its potential applications in anticounterfeiting and latent fingerprinting,” CHRIST (Deemed To Be University) Institutional Repository, accessed June 18, 2026, https://archives.christuniversity.in/items/show/22451.

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