Electrochemical sensor based on gold nanoparticles fabricated molecularly imprinted polymer film at chitosan–platinum nanoparticles/graphene–gold nanoparticles double nanocomposites modified electrode for detection of erythromycin

A molecularly imprinted electrochemical sensor was fabricated based on gold electrode decorated by chitosan–platinum nanoparticles (CS–PtNPs) and graphene–gold nanoparticles (GR–AuNPs) nanocomposites for convenient and sensitive determination of erythromycin. The synergistic effects of CS–PtNPs and GR–AuNPs nanocomposites improved the electrochemical response and the sensitivity of the sensor. The molecularly imprinted polymers (MIPs) were prepared by HAuCl4, 2-mercaptonicotinic acid (MNA) and erythromycin. Erythromycin and MNA were used as template molecule and functional monomer, respectively. They were first assembled on the surface of GR–AuNPs/CS–PtNPs/gold electrode by the formation of Au–S bonds and hydrogen-bonding interactions. Then the MIPs were formed by electropolymerization of HAuCl4, MNA and erythromycin. The sensor was characterized by cyclic voltammetry (CV), scanning electron microscope (SEM), UV–visible (UV–vis) absorption speactra and amperometry. The linear range of the sensor was from 7.0×10−8 mol/L–9.0×10−5 mol/L, with the limit of detection (LOD) of 2.3×10−8 mol/L (S/N=3). The sensor showed high selectivity, excellent stability and good reproducibility for the determination of erythromycin, and it was successfully applied to the detection of erythromycin in real spiked samples.

► A selective electrochemical molecularly imprinted sensor for the detection of erythromycin was developed.
► CS–PtNPs and GR–AuNPs nanocomposites were used to improve the sensitivity of the sensor.
► AuNPs was introduced in the preparation processes of MIPs films to improve the current response of MIPs.
► We combined self-assembly technology and electropolymerization method together in the preparation processes of MIPs.
► The sensor showed high selectivity, excellent stability and good reproducibility for the determination of erythromycin.