Hydrogen-bond activated ESIPT in naphthalimide-based fluorescent probe for sensing volatile amines

Area of Science:

• Analytical Chemistry
• Materials Science
• Food Science

Background:

• Amine levels are critical indicators for food safety and human health.
• Elevated amine levels can lead to pathological responses.
• Existing methods for volatile amine detection can be cumbersome.

Purpose of the Study:

• To develop a recyclable visual packaging bag for detecting volatile amines.
• To create a portable and efficient method for assessing food freshness.
• To elucidate the photoluminescence (PL) mechanism of the sensing material.

Main Methods:

• Synthesis of naphthylamide derivative N-S with positive photoluminescence (PL) characteristics.
• Fabrication of handmade test strips using compound N-S.
• Application of test strips for fish freshness labeling.
• Cyclic fumigation experiments to assess recyclability and efficiency.
• Density Functional Theory (DFT) calculations, titration mass spectrometry, and 1H NMR to investigate the PL mechanism.

Main Results:

• The N-S compound exhibits reversible PL properties, enabling its use in a recyclable packaging.
• Test strips effectively labeled fish freshness.
• The mechanism involves hydrogen-bond-activated Excited-State Intramolecular Proton Transfer (H-ESIPT).
• The method provides a portable and visual detection for volatile amines.

Conclusions:

• A recyclable visual packaging system for volatile amine detection was successfully developed.
• The N-S based test strips offer a promising portable solution for food freshness monitoring.
• Understanding the H-ESIPT mechanism enhances the design of novel sensing materials.