Applications of surface-enhanced Raman spectroscopy in the analysis of nanoparticles in the environment†
The rise of nanotechnology has introduced a large number of nano-enabled consumer products into the market. Stakeholders either interested in or concerned about the applications of nanoparticles (NPs) have questions on their exposure pathways, behavior and fate in the environment. Currently, detection and analysis of NPs in complex environmental samples are difficult and challenging. This review summarizes the emerging attempts to use surface-enhanced Raman spectroscopy (SERS) as a valuable tool for NP analysis. The critical factors influencing the feasibility of SERS for NP analysis are the material type, individual size, primary shape, surface chemistry and spatial arrangement of NPs. Current SERS methods for the identification, characterization and potential quantification of NPs are summarized and compared, with key limitations and issues recognized. Further, SERS applications in investigating the environmental behavior and fate of NPs are discussed. Probing and monitoring NPs using SERS yields important insights into the roles that NPs play in the environment. By studying the potential of SERS to detect NPs and track their environmental behavior and fate, environmental scientists are able to achieve an in-depth understanding of the benefits and risks of NPs. Also, knowledge from SERS can guide the nanotechnology research community to develop and apply NPs in a safe and effective manner. With an outlook on the key challenges and potential solutions in the end, this review is expected to appeal to a broad audience in the fields of nanotechnology, interfacial chemistry, analytical chemistry, soil science, environmental science, food science, and nanotoxicology.