Ultra-trace detection of methimazole by surface-enhanced Raman spectroscopy using gold substrate

Gold nanoparticles (AuNPs) were set up by a reduction technique and fabricated as SERS substrates for methimazole detection, which is of therapeutic significance. The morphology of the nanoparticles were characeterized utilizing Fourier Transform Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM), UV–vis spectroscopy, Scanning Electron Microscopy (SEM) and Raman spectroscopy. The regular size of the AuNPs was around 10 nm. The maximum absorbance for the UV–vis spectrum appeared at 524 nm. Density Functional Theory (DFT) computations and surface Enhanced Raman Spectroscopy (SERS) were used to study to the adsorption behavior of methimazole on the AuNPs substrates. SERS experiment and DFT calculations suggested the possibility of molecular interactions between the AuNPs and methimazole. SERS experiment showed an improvement in the bands which was used to obtain a rectilinear relationship between the concentration of methimazole and the intensity of the SERS signal. AuNPs showed a good coefficient of correlation and improved limit of detection.