Optical Detection of Herbicides in Water using Dye-Modified Single Walled Carbon Nanotubes

Hybrid materials were produced by mixing CuPcR₄ with acidified single-walled carbon nanotubes (SWCNTs) and characterised by UV-Vis absorption spectroscopy, scanning electron microscopy and atomic force microscopy. Thin films of pristine CuPcR₄ and SWCNT/CuPcR₄ were prepared by spin coating onto gold-coated glass slides and applied as active layers to detect pentachlorophenol (PCP), 2-chlorophenol, diuron and simazine in water utilizing Total Internal Reflection Ellipsometry (TIRE) as an optical detection method. Different concentrations in water ranging from 0.5 to 20 μg/L have been examined in the current work. It is revealed that the shifts in Δ(λ) spectra of SWCNT/CuPcR₄ films were evidently larger than those produced by the pristine CuPcR₄ films, indicating largely improved films’ sensitivity of the hybrid films.