Reactive deep eutectic solvents: Refining lignocellulosic biomass of wheat straw into nano building blocks for a more...

Refining lignocellulosic biomass into functional building blocks in a controlled manner offers an innovative strategy and opportunity for the fabrication of biomass-based materials. However, the complex nature and recalcitrant structure of lignocellulosic biomass hinder their upgrading route. Here we propose a "deconstruction-assembly" strategy to refine low-value wheat straw into nano building blocks, specifically nitrogen-doped carbon quantum dots (N-CQDs) and lignin-containing cellulose nanofibers (LCNFs), for the production of versatile biomass-based sensor through a novel reactive deep eutectic solvents (DESs) refining. The DESs, composing of monoethanolamine and choline chloride, function both as solvents and reactants for lignin extraction and amination. The waste liquid fraction, containing residual aminated lignin, soluble hemicellulos, and their degradation products are used as precursor for N-CQDs preparation, while the purified cellulose is used for LCNFs production. These nano-building blocks are then employed in the fabrication of a functional temperature sensor, exhibiting high responsivity (2.26 % °C^-1), linearity (R² = 0.995), stability, and fluorescent anti-counterfeiting properties, which is highly potential for smart food package applications.