Highly selective histamine assay via SERS: Based on the signal enhancement of carbon dots and the fluorescence quenching of gold nanoparticles

Fluorescent background is a major obstacle in surface-enhanced Raman scattering (SERS) and limits its application in various fields of science. This research developed a novel strategy by combining the advantages of the carbon dots (CDs) and gold nanoparticles (AuNPs) to increase the SERS signal for histamine (His) detection. The β-cyclodextrin (β-CD) decorated N,Zn co-doped carbon dots (N,Zn-CDs/β-CD) was prepared, which has both highly selective fluorescence (FL) sensitization and selective Raman signal enhancement for His derivatives (D-His). The prepared AuNPs not only could be used to enhance SERS signal, but also could quench 76% of the FL background at 544 nm, which is conducive to suppress the FL interference caused by carbon dots. Interestingly, the SERS signal increased with the gradual quenching of FL through the energy transfer between the fluorophore and the AuNPs. The combination of AuNPs and N,Zn-CDs/β-CD shows a detection limit of His around 10 μM, and a selectivity and anti-interference capability for His detection in the present of metal ions, sugar and other biogenic amines. This work exhibits the potential for anti-interference, sensitive and selective detection of His in practical SERS applications.