Electrochemical immunosensor based on screen-printed electrodes modified with gold nanoparticles for highly sensitive detection of TGF-α

• Develops a low-dimensional gold nanomaterial-modified electrochemical platform for immunosensing. • Demonstrates high sensitivity 0.051 mA·mL·pg⁻¹ and an ultra-low detection limit 0.35 pg mL⁻¹ for TGF-α. • Exhibits a wide linear detection range 1–1000 pg mL⁻¹, suitable for clinical quantification. • Shows excellent sensitivity and selectivity for ultra-sensitive, personalized diagnostics. Transforming Growth Factor Alpha (TGF-α) is a critical biomarker associated with various malignancies and pathological conditions, including cancer and other diseases. For efficient diagnosis and therapeutic monitoring, TGF-α in clinical serum must be detected accurately. In this study, we present a highly sensitive and selective electrochemical immunosensor for the detection of TGF-α, leveraging the principles of immunorecognition and advanced signal transduction. The immunosensor was constructed by immobilizing monoclonal anti-TGF-α antibodies via EDC-NHS chemistry onto a screen-printed electrode surface modified with gold nanoparticles to enhance electron transfer and provide a high surface area for antibody binding. Gold nanomaterials were characterized by UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), Dynamic light scattering (DLS), and Transmission electron microscopy (TEM) to confirm their morphology and size. Cyclic voltammetry (CV) and X-ray photoelectron spectroscopy (XPS) were employed to characterize the electrode modifications, ensuring stability and functional integrity. The developed sensor demonstrated excellent analytical performance, with a detection limit of 0.35 pg mL⁻¹, a linear range of 1–1000 pg mL⁻¹, and a high sensitivity of 0.051 mA. The immunosensor demonstrated high specificity, with negligible interference from other serum proteins, and robust repeatability. The sensor retained about 98% of its original response after storage at 4°C for 1 week, demonstrating acceptable long-term stability of the functionalized platform. This study underscores the potential of electrochemical immunosensors as a promising platform for the point-of-care diagnostics of TGF-α, enabling timely and accurate disease management. Future advancements may integrate multiplex detection capabilities and real serum analysis for broader clinical applicability and real-world applications.