PEGylated Network Nanostructured by Gold Nanoparticles for Electrochemical Sensing of Aromatic Redox and Nonredox Analytes

Polish National Science Center (Project No. 2021/43/B/ST4/00533); Polish National Science Center (Project No. 2011/01/N/ST5/05550)

We present the design, tailoring, and physicochemical properties of a multicomponent polyethylene glycol (PEG)-based polymer doped with spherical nanoparticles modified with a lipoic acid derivative of cyclodextrin and its application for the electrochemical sensing of a ferrocene derivative and ibuprofen at low concentrations. Each of the components of this hybrid material has specific properties that can be useful for the preparation of sensors characterized by high selectivity and a low detection limit. Electrochemical studies have previously shown that the cyclodextrin derivative with an aromatic triazole linker in the structure enhances binding of the analyte, ensuring its preconcentration on the electrode and, therefore, enabling improvement of the sensor detection limit. On the other hand, the introduction of evenly dispersed spherical gold nanoparticles in the polymer matrix increases the conductivity of the film and enhances the analytical signal. The third component─a biocompatible and easily wettable cross-linker, PEG─allows for uninterrupted diffusion within the polymer film. This significantly increases the analytical performance of the sensor, supports further improvement of the detection limit, and enables the determination of the analyte after saturation of cyclodextrin cavities (high concentration of analyte) based on its diffusion response. The designed hybrid material was used for the direct and indirect determination of aromatic analytes─ferrocene derivative and ibuprofen─with a very low detection limit.