Sensitive detection of dextromethorphan hydrobromide based on portable Raman spectrometer and CuO@AgNPs nano composite SERS substrate

A highly sensitive surface-enhanced Raman spectroscopy approach was established for the detection of dextromethorphan hydrobromide (DXM) utilizing nano CuO modified silver nanoparticles (CuO@AgNPs) as substrate. Ultraviolet visible spectra (UV-vis), X-ray diffraction (XRD) and transmission electron microscopy (TEM) characterized the synthesized CuO@AgNPs. UV-vis and fourier transform infrared (FT-IR) were adopted to investigate the interaction between DXM and CuO@AgNPs. The optimal experimental conditions (the dosages of CuO@AgNPs and NaCl as well as mixing time) were explored. The enhancement factor (EF) was 1.71 × 10 6 . The linear relationship between SERS intensity and the concentration of DXM in the range of 67 – 1000 nmol L −1 was obtained as I SERS = 25.81 c + 40398.77, and the limit of detection (LOD) was 2.12 nmol L −1 (S/N = 3). The interference of K + , Mg 2+ , Zn 2+ , Ca 2+ , Cu 2+ , Fe 3+ , glucose, HSA, L-tryptophan, soluble starch and ibuprofen were investigated. The method was successfully applied to test DXM in serum samples. The recovery was 99.06% – 101.51% with the relative standard deviation (RSD) of 0.74% – 3.87%.