Nonconventional Fluorescent Non-Isocyanate Polyurethane Foams for Multipurpose Sensing Applications

Area of Science:

• Materials Science
• Analytical Chemistry
• Polymer Chemistry

Background:

• Fluorescent foams are useful for detection but often limited by probe costs, aggregation-caused quenching, and incorporation difficulties.
• Traditional fluorescent probes require external addition and can be inefficient in solid-state applications.

Purpose of the Study:

• To develop intrinsically fluorescent non-isocyanate polyurethane (NIPU) foams for sensing applications.
• To explore the unique multicolor emission properties of these NIPU foams.
• To demonstrate the utility of these foams for detecting and quantifying various analytes.

Main Methods:

• Preparation of NIPU foams via a water-induced self-blowing process.
• Characterization of intrinsic multicolor fluorescence and photoluminescent properties.
• Application of foams for sensing gaseous formaldehyde, metal ions (Fe2+, Cu2+, Fe3+, Hg2+), and tetracycline antibiotics.
• Development of a smartphone-compatible device for antibiotic quantification.

Main Results:

• NIPU foams exhibit intrinsic multicolor fluorescence without external probes, overcoming aggregation-caused quenching.
• Foams successfully captured and sensed formaldehyde, various metal ions, and selectively detected tetracycline antibiotics with high sensitivity.
• A smartphone-based device enabled facile quantification of antibiotics by exploiting the foams' photoluminescent properties.

Conclusions:

• Easily synthesized NIPU foams possess inherent, tunable fluorescence due to clusteroluminescence from hydrogen bonding and hetero-atomic sub-luminophores.
• These non-conventional fluorescent foams show significant potential for multi-analyte detection and quantification in environmental and biological applications.
• The developed foams offer a cost-effective and straightforward alternative to traditional fluorescent probes for sensing applications.