Screening of single-walled carbon nanotubes by optical fiber sensing

A methodology based on optical fiber (OF) sensing was developed to screen single walled carbon nanotubes (SWCNT) in aqueous solutions. This method was validated by the comparison of its analytical performance with that of an ultraviolet-visible (UV-Vis) technique by monitoring the absorbance intensities at 500 nm, and no significant difference (p=0.854) was observed between such two methods. The results obtained by the OF sensor were encouraging in what concerns a new approach for detection and quantification of SWCNT in solutions due to its compact design, less expensive materials and equipment, as well as a requirement of low volume of sample. Additionally, it was concluded that the nonlinear calibration model observed for the analytical response with the OF probe follows the general cumulative symmetric double sigmoidal (SDS) model (R(2)=0.9999), once adapted for the analytical region of interest.