Fluorescent probe for Fe(iii) based on pyrene grafted multiwalled carbon nanotubes by click reaction

The attempt to decorate carbon nanotubes with organic molecules to form new functional materials has attracted broad attention in the scientific community. Here, we report the covalent functionalization of multiwalled carbon nanotubes (MWCNTs) with pyrene via Cu(i)-catalysed azide/alkyne click (CuAAC) reactions under mild conditions to afford the nanocomposites of pyrene-MWCNTs. Fourier transform infrared spectroscopy (FT-IR), ultraviolet and visible spectroscopy (UV-Vis), and fluorescence spectroscopy were used to characterize the nanocomposites of pyrene clicked MWCNTs. Experimental results indicate that the CuAAC reaction occurs in an efficient manner and the spacer linking MWCNTs and the photoactive molecule is well defined. In contrast to the noncovalent functionalization of π-π stacking, the nanocomposites of pyrene clicked MWCNTs show relatively strong fluorescence and have potential applicability in photoluminescent devices as a highly sensitive and selective fluorescence "turn-off" sensor for Fe³⁺.