A flexible SERS substrate for highly sensitive detection of aromatic volatile organic compounds

Long-term exposure to aromatic volatile organic compounds (VOCs) will create a lot of damage in the body, making their efficient collection and highly sensitive detection a crucial task. Herein, we developed a flexible surface-enhanced Raman scattering (SERS) substrate by loading gold nanoparticle multimers onto oil blotting paper (Au NPs-OBP) for the highly sensitive detection of aromatic VOCs. Leveraging a hydrophobic surface and similarity compatibility principle, the substrate facilitates efficient adsorption of trace aromatic VOCs from human skin. The coagulation of the OBP further causes tight aggregation of Au NPs, anchoring them firmly to the fibers and generating dense hot spots for SERS enhancement. The Au NPs-OBP substrate confirms high sensitivity, with limits of detection (LOD) of 4.628 × 10 −11  M and 9.422 × 10 −9  M for Rhodamine 6G (R6G) and p-nitrophenol (4-NP), respectively. Finite difference time domain (FDTD) simulations demonstrated that the substrate possesses a homogeneous high local electromagnetic field. Excellent reproducibility was achieved across randomly selected spots on the same substrate and among substrates from different batches. The LOD for catechol was found to be 6.657 × 10 −12  M, and the recovery rate improved further, varying between 89.26% and 97.09%. These results indicate that the Au NPs-OBP substrate is a promising platform for the highly sensitive detection of the aromatic VOCs.