Electrochemical Detection of Penicillin G Using a Nanomolecularly Imprinted Polymer Sensor Modified with Carbon Nanofibers and Gold Nanowires

Abstract This study explores the electrochemical behavior of nanomolecularly imprinted polymers (NMIPs) integrated with carbon nanofibers (CNFs) and gold nanowires (AuNWs) modified on screen-printed carbon electrodes (SPCEs) using cyclic voltammetry, electrochemical impedance spectroscopy, and differential pulse voltammetry for the determination of penicillin G. The incorporation of CNFs and AuNWs enhanced electron transfer and improved the electrocatalytic performance of the modified sensor. NMIPs act as artificial biomarkers that selectively bind to the target analyte, penicillin G. Bare and modified SPCEs were characterized using [Fe(CN)6]3–/4– as a redox probe in 1 M KCl. The chemical composition and surface morphology of the nanomaterials were further characterized using field-emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction analysis. The CNFs/AuNWs/SPCE-modified sensor showed a 2.35-fold increase in current compared with the bare electrode. The fabricated CNFs/AuNWs/NMIPs/SPCE sensor demonstrated a strong linear response over the range of 0.001–30 μM (R2 = 0.9892), with a detection limit of 1.0 nM. Furthermore, the sensor exhibited excellent selectivity toward penicillin G, along with good reproducibility (1.14%), stability, and satisfactory recovery rates (92%–98%) in pharmaceutical products. This sensor shows significant potential for penicillin G detection and may be applied in future pharmaceutical industry applications.