Determination of paclobutrazol using square wave voltammetry based on a molecularly imprinted polymer and boron-doped copper oxide/graphene nanocomposite†

Abstract

In the present study, a novel voltammetric sensor based on a boron-doped copper oxide/graphene (B-CuO-Gr) nanocomposite and molecularly imprinted polymer (MIP) was developed for the detection of paclobutrazol (PAC) in apple and orange juice samples. The B-CuO-Gr nanocomposite was prepared using sol–gel and calcination methods. After modifying glassy carbon electrodes with the B-CuO-Gr nanocomposite, PAC-imprinted electrodes were prepared in the presence of 100.0 mM pyrrole (Py) monomer and 25.0 mM PAC using cyclic voltammetry (CV). After elucidating the surface properties of the prepared B-CuO-Gr nanocomposite and PAC-imprinted electrodes using various characterization techniques, the PAC-imprinted sensor was successfully applied to apple and orange juice samples, demonstrating high recovery. A linear range of 1.0 × 10⁻⁹ to 1.0 × 10⁻⁸ M PAC (R² = 0.9983) and a detection limit (LOD) of 3.30 × 10⁻¹⁰ M were observed, along with high selectivity, stability, and reproducibility for the MIP/B-CuO-Gr/GCE sensor.