Luminol-capped cerium nanoparticle aggregates for fluorescent detection of morpholine in fresh fruits

Luminol-capped cerium aggregated (Ce-Lum) nanoparticles have been developed as a selective fluorescent sensor for
detecting morpholine in fruits and vegetables. Synthesized through a simple one-step ambient process, these nanoparticles
combine the unique properties of cerium ions (Ce³⁺/Ce⁴⁺) and luminol. Cerium ions act as efficient electron acceptors,
enabling charge transfer interactions, while luminol serves as a strong fluorophore with reactive sites for morpholine
binding. Upon aggregation, the hybrid nanostructure enhances energy transfer and surface passivation, suppressing non-
radiative recombination and improving quantum yield. This synergistic mechanism results in high signal intensity and
ultralow detection limits, even in the presence of interfering species. The sensor exhibits excellent sensitivity, specificity,
and selectivity, achieving accurate morpholine detection in complex food matrices. Recovery rates close to 100% and
relative standard deviation (RSD) values below 3% confirm its precision and reliability. Demonstrating a linear response
with a strong correlation coefficient (R² = 0.981), the system achieves an exceptionally low detection limit of 0.08 ppb.
These results highlight the sensor as a significant advancement in morpholine detection, offering potential for food safety
monitoring, environmental tracking, and industrial applications. Its superior performance bridges gaps in real-time con-
taminant detection, ensuring quality and safety assurance