Ionic liquid functionalized 3D graphene-carbon nanotubes‒AuPd nanoparticles‒molecularly imprinted copolymer based...

An innovative electrochemical sensor for paracetamol (PCM) determination was fabricated by electropolymerization imprinting on three-dimension (3D) AuPd nanoparticles‒ionic liquid (IL) functionalized graphene‒carbon nanotubes nanocomposite (AuPd/GN-CNTs-IL) modified glassy carbon electrode. The GN-CNTs supported AuPd alloy nanoparticles were prepared via one-pot hydrothermal method in the presence of IL (i.e. 1-hydroxyethyl-3-methyl imidazolium bis[(trifluoromethyl) sulfonyl] imide), which not only promoted the formation of small AuPd alloy nanoparticles, but also acted as "spacer" to prevent the π-π stacking and aggregation of graphene sheets and carbon nanotubes. The resulting composite had large surface area and high electrocatalysis. The PCM imprinted poly(carbazole-co-pyrrole) exhibited good recognition to PCM and had high stability. Based on the synergic effect of PCM imprinted copolymer and 3D AuPd/GN-CNTs-IL nanocomposite, a highly selective and sensitive electrochemical sensor was established. It presented a good linear relationship from 0.10 to 10 μM with a low limit of detection of 50 nM (S/N = 3). The sensor could be applied to the detection of PCM in biological samples, with acceptable recoveries (84.5%-102%). In addition, it was successfully used to monitor the concentration of PCM in urine from a patient with fever cold.