Electrochemical sensor based on in situ polymerized ion-imprinted membranes at graphene modified electrode for palladium determination

• An ion-imprinted sensor method for determination of Pd(II) was developed.
• An electrochemical sensor was constructed by Pd(II)-IIM modified G/GCE.
• One-step in situ polymerization method was used to form ion imprinted membrane.
• The sensor was successfully applied to detect Pd(II) in catalyst and plant samples.

In this work, an amperometric sensor was developed for the selective recognition and sensitive determination of palladium in complex matrices using a glassy carbon electrode (GCE) modified with a novel ion-imprinted membrane (IIM) and graphene. Graphene enhanced the sensor's electron transfer and sensitivity. The electrode surface was first directly modified with graphene through the electrodeposition of graphene oxide. An ion-imprinted polymer membrane was subsequently synthesized on this modified surface via in situ polymerization in acetonitrile using allylurea (NAU) as a functional monomer, ethylene glycol dimethacrylate (EGDMA) as cross-linking agent, and azobisisobutyronitrile as an initiator at a molar ratio of template (PdCl2) to NAU to EGDMA of 1:4:40. Amperometric i-t curves were measured for the determination of palladium. The designed modified electrode was shown a linear response to Pd(II) ions in the range of 2.0 × 10− 8–2.0 × 10− 4 mol L− 1 of Pd(II) ion with a detection limit of 6.4 × 10− 9 mol L− 1. Metal ions present at concentrations 15 times higher than that of Pd(II) did not interfere with the determination of Pd(II). The sensor was successfully applied to determine palladium in catalyst and plant samples with a relative standard deviation (RSD) of less than 3.3% (n = 5) and recoveries in the range of 99.2–106.5%.

A novel amperometric sensor was constructed by in situ polymerization of Pd(II)-imprinted membranes on the surface of graphene modified glassy carbon electrode using allyluread (NAU) as functional monomer, ethylene glycol dimethacrylate (EGDMA) as cross-linking agent. The electrochemical characteristic of the sensor was characterized by CV and i-t curve. The sensor exhibited a good selectivity, high sensitivity.Figure optionsDownload as PowerPoint slide