Copper phthalocyanine/single walled carbon nanotubes hybrid thin films for pentachlorophenol detection

Abstract

Tetra-substituted copper phthalocyanine (CuPcR4, R=−S(CH2)15CH3) has been prepared and characterised by UV–Vis, FT-IR and mass-spectrometry. 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) in water utilizing total internal reflection ellipsometry (TIRE) technique. Different concentrations of PCP in water ranging from 0.5 to 10μg/l have been examined in the current work. It is revealed that the phase shift (Δ(λ)) spectra of SWCNT/CuPcR4 films were two times larger than the shifts produced by the pristine CuPcR4 films with clear recovery in the Δ(λ) spectra after flushing the cell with water. The adsorption of PCP on both types of films is discussed and films’ sensitivity was determined using the change in films’ refractive index.