A highly selective and sensitive detection of scopolamine using a functionalized gold nanoclusters-assisted molecularly imprinted polymer-based electrochemical sensor

Scopolamine (SCA), a tropane alkaloid isolated from the Solanaceae family, acts as an antagonist to muscarinic acetylcholine receptors due to its structural similarity to acetylcholine. Its anticholinergic properties make scopolamine widely used in medicine. In this work, a sensitive and precise detection of SCA is achieved using an electrochemical sensor based on molecularly imprinted polymers (MIPs) supported by nanomaterials. The sensor was produced using a photopolymerization (PP) approach on a glassy carbon electrode (GCE) using SCA as a template and 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS) as a functional monomer. The MIP-based electrochemical sensor's active surface area and porosity were enhanced by adding gold nanoclusters (AuNCs). Electrochemical and morphological evaluations of the SCA/AMPS/AuNCs/MIP-GCE sensor were conducted using scanning electron microscopy (SEM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The SCA in the linear range of 2.50 - 17.50 pM was determined using the indirect measuring approach using 5.0 mM [Fe(CN)6]3-/4- solution. The designed sensor showed remarkable linearity and highly sensitive limit of detection (LOD) and limit of quantification (LOQ) values in both standard solutions and biological media. Its reliability was confirmed by excellent repeatability and reproducibility, with relative standard deviations ranging from 0.94 % to 2.35 %. Additionally, the sensor exhibited high specificity, successfully distinguishing SCA from structurally similar molecules. The green profile score in this study was also determined using Analytical Greenness Assessment Tool for Molecularly Imprinted Polymers Synthesis (AGRREMIP).