SERS and SEIRA Detection of Polycyclic Aromatic Hydrocarbons and their Derivatives in Murine Tissues: Bioaccumulation and Clearance.

The toxicological effects of polycyclic aromatic hydrocarbons (PAHs) and polycyclic aromatic compounds (PACs) have attracted considerable research interest due to their known bioaccumulation. However, time-resolved and longitudinal studies that examine in vivo bioaccumulation and clearance remain limited. Here we use Surface-Enhanced Raman Scattering (SERS) and Surface-Enhanced Infrared Absorption (SEIRA) spectroscopies to detect and track the presence of two PAHs: pyrene, benzo[a]pyrene, and one PAC: 5,12-naphthacenequinone, in murine organ tissues. Mice were exposed to a three-component mixture of these three chemicals, then their organs were collected at 24-, 48-, and 72- hours post-exposure. The accumulation of each of these chemicals in the brain, liver, kidneys, heart, and spleen over a 72-hour post-exposure period was determined by SERS and SEIRA and independently quantified by gas chromatography-mass spectrometry (GC-MS) analysis. The liver and kidneys displayed the highest level of accumulation, reflecting their important roles in detoxification, while significant levels were detected in the brain, indicating permeability of the blood-brain barrier and the potential for neurotoxic effects. Benzo[a]pyrene showed the highest retention and slowest clearance, while 5,12-naphthacenequinone showed surprisingly minimal bioaccumulation. The independent detection of benzo[a]pyrene-induced DNA adducts in multiple organs also highlights its mutagenic and carcinogenic risk.