Synthesis and application of dendritic Pt-Pd bimetallic nanoparticles in imprinted electrochemical sensor for the determination of florfenicol

Abstract In this work, the formation mechanism of dendritic Pt-Pd bimetallic nanoparticles (NPs) with perpendicular pore channels in aqueous medium was investigated using hexadecylpyridinium chloride (HDPC) and hexamethylenetriamine (HTM) as structure-directing agents. The results indicated that reaction temperature impacted the properties of the bimetallic components and the particle diameter, while the amount of ascorbic acid (AA) and reaction time impacted the diameter and the amount of HTM determined the pore size. Porous N-doped graphene (N-P-r-GO) was used to load the dendritic Pt-Pd NPs to form a porous and three-dimensional structure on glassy carbon electrode (GCE). As a result, Pt-Pd NPs-N-r-GO / GCE was obtained. Florfenicol (FOL) was imprinted on the modified electrodes using cyclic voltammetry (CV) since indole-5-carboxylic acid was a novel monomer, and FOL functions as a template molecule. The molecularly imprinted polymer (MIP) / Pt-Pd NPs-N-r-GO / GCE was successfully obtained by eluting the template molecule from the polymer, and Fe(CN)63−/4− was used to detect the impedance signal for the recognition of FOL. This sensor exhibited excellent response for FOL in the linear range of 5.0 × 10-8 ∼ 8.0 × 10-6 mol L-1 with detection limit of 1.0 × 10-9 mol L-1. The obtained sensor also exhibited excellent response for FOL detection in real samples.