DFT, Raman, FTIR, and SERS Spectroscopic Study of Trenbolone Acetate

The inadequacy of reference standards and spectral libraries makes it challenging to develop new spectroscopicbased analytical approaches that can be used by the World AntiDoping Agency (WADA) in its antidoping efforts. In this study, trenbolone acetate, which is a commonly abused steroid molecule in sports, was investigated. The molecule was spectroscopically characterized using Raman (Conventional and surfaceenhanced Raman) and Fouriertransform infrared spectroscopies. SERS was based on the locally synthesized pristine silver nanoparticles as substrates. Density functional theory (DFT) calculations were used to interpret the experimental Raman and FTIR results. Prominent bands centered around wavenumbers 894 cm−1, 1578 cm−1, 1654 cm−1, and 1729 cm−1 (assigned to C = O and C = C) were observed in both FTIR, Raman, and SERS. The spectral region of 1400 cm−1 to 1800 cm−1 was the most active, with the majority of bands (1406 cm1, 1471 cm−1, 1502 cm−1, and 1654 cm−1) being isoenergetic between the IR and Raman spectra. These bands could serve as vibrationalbased biomarkers in routine, rapid doping analysis. In conclusion, combining Raman, FTIR, SERS, and DFT enabled the spectral characterization of trenbolone acetate and facilitated a subsequent enhancement assessment that can be utilized for future analytical purposes in doping detection.