A molecularly imprinted electrochemical sensor for ovalbumin based on flower-like CuS nanomaterials

A molecularly imprinted electrochemical sensor (SPCE@CuS/MIPs) for the quantitative detection of ovalbumin (OVA) was designed based on a CuS-modified screen-printed carbon electrode. CuS with a flower-like structure is conducive for increasing the specific surface area and adsorption capacity of the material and therefore improving the electrochemical response of the sensors. The imprinted polymers were deposited on the surface of SPCE@CuS by the electropolymerization method in the presence of polydopamine (PDA) and OVA. The morphology and chemical composition of the imprinted film were characterized via scanning electron microscopy and X-ray photoelectron spectroscopy. Furthermore, the electrochemical performance of the sensor was investigated by cyclic voltammetry and electrochemical impedance spectroscopy. Under optimal conditions, the SPCE@CuS/MIPs sensor demonstrated a linear detection range of 10-600 μM for OVA with a detection limit of 0.84 μM (S/N = 3). The sensor also exhibited excellent selectivity, reproducibility and stability. Finally, the method was successfully applied to the determination of OVA in egg white with satisfactory recoveries. This study provides a sensitive and efficient method for the determination of OVA.