2D/0D Heterojunction Fluorescent Probe with Schottky Barrier Based on Ti₃C₂T_X MXene Loaded Graphene Quantum Dots for Detection of H₂S During Food Spoilage

Abstract Hydrogen sulfide (H 2 S) contamination of food has raised widespread public health concerns, leading to substantial medical and economic burdens. Herein, a 2D/0D heterojunction fluorescent probe (TCTG) with Schottky barriers (SB) is designed and synthesized, utilizing Ti 3 C 2 T x MXene‐loaded graphene quantum dots (GQDs), for the detection of H 2 S during food spoilage. The microstructures observed through SEM and TEM reveal that uniformly sized GQDs are evenly attached to the surface of a monolayer Ti 3 C 2 T x . The chemisorption between GQDs and Ti 3 C 2 T x facilitates charge transfer and the formation of SB, resulting in intramolecular charge transfer (ICT) effects. With the introduction of H 2 S, TCTG (50%) exhibits the highest sensitivity, selectivity, and anti‐interference properties, with ultra‐fast fluorescence transient reaction (3s) and remarkably low detection limit of 41.82 ppb as well as noticeable color change. When TCTG (50%) reacted with H 2 S, the ICT effects are inhibited, leading to the recovery of photoinduced electron transfer (PET) and fluorescence quenching. Notably, probe TCTG is effectively utilized to detect changes in H 2 S levels in raw foods to assess their quality. Overall, the significance of this study is its potential to revolutionize food spoilage detection, offering a fast, reliable, and sensitive method to ensure food safety and reduce associated health and economic burdens.