Pyrazine-based hollow spherical self-assemblies: A portable tool for detection of volatile organic amines

Development of easy and efficient sensing tool for instant detection of various organic amines in aqueous media has prime significance. In this context, hollow spherical H-aggregates of pyrazine derivative bearing terminal acetyl groups were demonstrated as a reaction-based vapor phase sensing tool for organic amines. The aggregates displayed ratiometric fluorescence behavior toward aliphatic amines with a detection limit at nanomolar concentrations with concomitant self-assembly modulation from spherical H-aggregates to rod-shaped J-aggregates. Surprisingly, in the presence of p-nitroaniline remarkable quenching response was observed among various aromatic amines, which is attributed to the inner filter effect and energy transfer. Furthermore, a portable efficient tool for sensing various organic amines was constructed using the aggregates, demonstrating the practical applicability of this approach. This work will provide straightforward way for designing multifunctional self-assemblies for efficient selective behavior toward various organic amines in the ground water bodies.