Unravelling the Mechanism of Cluster-Triggered Emission in Carboxy Nanocellulose and Modulation through the Conjugation of Plasmonic Nanoparticles for Analyte Detection

Abstract

Cluster-triggered emission (CTE) by through-space interactions (TSIs) in nonaromatic and nonconjugated molecular systems gathered remarkable interest recently due to the possibility of creating white light emissive diodes with cost-effective and environmentally friendly materials and methods. Cellulose nanocrystals (CNC), obtained in an environmentally friendly way from agricultural wastes such as rice and wheat straws, were explored to understand the mechanism of CTE by TSI in varying experimental conditions such as pH, solvent, concentration, and excitation light wavelength. We have also explored the effect of CTE of CNC in the presence of plasmonic nanoparticles such as Ag. Moreover, efforts were made to justify the experimental observations with theory, especially the energy gap between the valence and the conduction bands in the clustered states of CNC and the possibility of intra- and intermolecular n····n and n····π* interactions. Lastly, we have shown clustered carboxy cellulose nanocrystals (cCNC) as a novel material for the fluorescence-based detection of uric acid with a micromolar detection limit.