A novel composite of molecularly imprinted polymer-coated PdNPs for electrochemical sensing norepinephrine

• A novel composite of MIP-coated PdNPs for electrochemical sensing of norepinephrine was described.
• The MIP-coated PdNPs sensor possessed high current response for norepinephrine.
• Comparison results of MIP-coated PdNPs and MIP without PdNPs sensors showed the function of PdNPs.
• The MIP-coated PdNPs sensor could recognize norepinephrine from its analogs.
• Low detection limit of MIP-coated PdNPs sensor for norepinephrine was obtained.

A novel composite of molecularly imprinted polymer-coated palladium nanoparticles (MIP-coated PdNPs) was synthesized by sol–gel method using norepinephrine as template, phenyl trimethoxysilane as functional monomer and tetramethoxysilane as crosslinker. The combination of PdNPs and silica-based MIP endowed the composite with good electrochemical catalytic property, large surface area and template selectivity. MIP-coated PdNPs were characterized by Fourier transform infrared spectroscopy and Transmission electron microscopy. Then MIP-coated PdNPs composite was used as a recognition element in the construction of an electrochemical sensor for norepinephrine. The properties of MIP-coated PdNPs sensor such as special binding, adsorption dynamics and selective recognition ability were evaluated by differential pulse voltammetry. The results demonstrated that MIP-coated PdNPs sensor not only possessed a short response time, but also high binding capacity for norepinephrine, which enabled the imprinted sensor with higher current response than that of non-imprinted material and MIP without PdNPs. In addition, the MIP-coated PdNPs sensor exhibited selectivity for norepinephrine in comparison to other analogs. The MIP-coated PdNPs sensor had a wide linear range over norepinephrine concentration from 0.5 to 80.0 μM with a detection limit of 0.1 μM. The MIP-coated PdNPs sensor was proved to be a suitable sensing tool for the fast, sensitive and selective determination of norepinephrine in injection and urine samples.