Specific adsorption and highly sensitive detection of methyl red in wastewater using an iron paste electrode modified with a molecularly imprinted polymer

Abstract

In this paper, an integrated system for specific adsorption of methyl red (MR) and sensitive detection of the residual amount of this dye in printing and dyeing wastewater is proposed. A molecularly imprinted polymer using MR as the template molecule (MR-MIP) was prepared for specific adsorption of MR from printing and dyeing wastewater. A solid-phase extraction column was filled with a paste of MR-MIP and cobalt-doped iron carbide nanoparticles as the working electrode to construct a highly sensitive sensor for MR detection. The distillation–precipitation approach was used to fabricate microspheres with molecularly imprinted surfaces using cellulose as the carbon source and methyl red (MR) as the template. Not only do the molecularly imprinted microspheres have a satisfactory adsorption performance for the template molecule MR, with a dynamic adsorption capacity up to 264.2 mg g−1, but also the electrochemical sensor built from the molecularly imprinted polymer and iron paste electrode, co-modified with nitrogen-doped carbonized iron nanoparticles, has great sensitivity for MR detection. It is very important to develop an integrated platform for dye treatment and residue detection in wastewater. This technique has a low detection limit and a broad linear range compared to other approaches.