Synthesis and Application of Ion‐Imprinted Nanoparticles in Electrochemical Sensors for Copper (II) Determination

Abstract We report here the synthesis and characterisation of ion imprinted polymers nanoparticles (nanoIIPs) and their application as electrochemical sensors for Cu²⁺ ions determination. Imprinted nanoparticles were developed following a free radical polymerisation in water and subsequently immobilised on the surface of gold screen printed electrodes (SPAuE). Characterisation of nanoIIPs was performed using dynamic light scattering (DLS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Electrochemical determination of Cu²⁺ was achieved in water samples using differential pulse voltammetry (DPV). Voltammetric responses demonstrate different current responses for copper(II)‐imprinted polymers nanoparticles (Cu‐nanoIIPs) and non‐imprinted polymer nanoparticles. The nanoIIPs sensor responds to copper (II) in a linear range between 1.9 and 61 nM, with a sensitivity of 0.0618 μA nM⁻¹. The limit of detection (LOD) and limit of quantification (LOQ) of the electrochemical sensor tested in buffer solution were 74 pM and 247 pM, respectively. Furthermore, the sensor presents high selectivity when tested against other ions such as Ni²⁺, Zn²⁺, NO₃⁻, and CrO₄²⁻, and it is potentially suitable for environmental monitoring of heavy metals and food control. The sensor responses were also successfully evaluated in spiked commercialised drinking water.