Sensitive Detection of Dopamine by Graphidyne/Laser‐Induced Graphene Nanoheterojunction Film Electrode

In this work, laser‐induced technology was utilized to convert polyimide films coated on indium tin oxide (ITO) substrates into laser‐induced graphene (LIG), thereby fabricating LIG/ITO electrodes. A 1 mg/mL graphdiyne (GDY) dispersion was subsequently deposited on the LIG/ITO surface through a drop‐casting strategy to prepare nanoscaled GDY/LIG/ITO electrochemical electrodes. The morphology and structural properties of the composite were systematically characterized by scanning electron microscope, transmission electron microscope, X‐ray photoelectron spectroscopy, and Raman spectroscopy. The analytical results demonstrated that GDY was uniformly immobilized on the surface of LIG to form a homogeneous composite film. Owing to the distinctive few‐layer GDY/LIG heterostructure, the optimized electrode exhibited an enlarged electrochemically active surface area and accelerated charge transfer efficiency. Accordingly, the sensor delivered excellent detection performance toward dopamine (DA), possessing a wide linear range of 1–1000 μM and a low limit of detection of 0.33 μM. Moreover, the fabricated sensor was successfully applied for the quantitative detection of DA hydrochloride injection samples, achieving acceptable recoveries ranging from 98.5% to 100.9%. These results verify that the GDY/LIG electrode possesses great potential for practical analytical applications.