Carbon nanotube profiling in biological media via advanced Raman spectroscopy techniques

The clinical application of carbon nanotube (CNT) based solutions has sparked debate within the scientific community, primarily due to concerns about their non-biodegradability, potential long-term toxicity and bioaccumulation in organs and tissues. A significant challenge in evaluating the health risks of CNTs is the lack of standardized guidelines for reliably assessing CNT concentrations in biological systems. Here, we explore the use of time-resolved Raman spectroscopy in association with partial least square (PLS) regression models to detect and quantify CNTs in biological systems. This study included a comprehensive assessment of the structural and chemical characteristics of different types and sources of CNTs. The results revealed that separate PLS models must be developed for each CNT source, as the same CNT type from different suppliers exhibited unique principal components due their varying characteristics. This study highlights the benefits of utilizing the unique Raman signature of CNTs in combination with PLS models to establish a standardized method for detecting and quantifying CNTs, potentially opening precedents for the regulatory frameworks concerning clinical use of CNTs.