Carboxyl purified single-walled carbon nanotubes are widely utilized in biomedical applications due to their enhanced biocompatibility and functionalization capabilities. They are often employed in drug delivery systems, where their high surface area and ability to be conjugated with therapeutic agents enable targeted and controlled release of drugs. Additionally, these nanotubes are used in biosensors for detecting biomolecules, as their electrical properties can be tailored to improve sensitivity and selectivity. In tissue engineering, they serve as scaffolds to promote cell growth and regeneration, thanks to their structural strength and ability to mimic the extracellular matrix. Furthermore, their use in imaging techniques, such as fluorescence and photoacoustic imaging, enhances diagnostic precision. In environmental applications, they are effective in water purification and pollutant removal due to their adsorption properties and chemical stability.