H2O2-assisted detection of melamine using fluorescent probe based on corn cob carbon dots-Ionic Liquid-Silver nanoparticles

• A sustainable method for the accurate detection of melamine has been developed. • Fluorescent probe was designed based on the interaction between H 2 O 2 and melamine. • The carbon dots of the fluorescent probe are derived from food waste - corn cob. • The detection limit for melamine is lower than the national standard method. • The method was proven to accurately detect melamine in real dairy products. In this work, a new sustainable melamine detection method was developed. Biomass-derived carbon dots (CDs) were successfully prepared by ionic liquid (1-Allyl-3-methylimidazolium chloride, IL) hydrothermal method using agricultural waste corn cob as the carbon source, and combined with silver nanoparticles (AgNPs) to construct fluorescent probe CDs@IL-AgNPs. The probe was characterized and the formation mechanism of the probe was discussed. The direct detection of H 2 O 2 and the indirect sensitive detection of melamine were realized. The detection limit of melamine was 0.94 μmol/L, which is far lower than the minimum allowable amount of melamine in milk powder (7.95 μmol/L). The high sensitivity and selectivity probe was used to detect melamine in commercial dairy products, and the recovery rate of standard addition was between 94% and 110%. This study provides valuable new application ideas for the detection of melamine in dairy products and the low-carbon and environmentally friendly treatment of agricultural waste.