A ratiometric fluorescence probe for melamine detection based on luminescence resonance energy transfer between the NaYF4:Yb, Er upconversion nanoparticles and gold nanoparticles

In this paper, a novel ratiometric fluorescence probe for melamine detection based on luminescence resonance energy transfer (LRET) between the NaYF 4 :Yb, Er upconversion nanoparticles (UCNPs) and gold nanoparticles (AuNPs) was developed. The detection mechanism could be interpreted to the AuNPs quenched the fluorescence intensity (F 542 and F 654 ) of the UCNPs under 980 nm excitation. after melamine addition, the fluorescence intensity of the UCNPs was recovered due to the aggregation of Au NPs. A good linear relationship between the ratio of F 542 to F 654 nm (F 542 /F 654 ) was obtained in ranges of 20-200 μg/L of the melamine concentration and the limit of detection was 8.8 nM. Besides, The probe exhibited an excellent selectivity and good sensitivity to melamine, and achieved the melamine detection in real sample. This work paved a new avenue for the potential practice application for commercial instantaneous determination of the melamine.