An impedimetric immunosensor based on PAMAM decorated electrospun polystyrene fibers for detection of interleukin-10 cytokine

Abstract

• Polystyrene (PS) fibers were electrospun and modified by air plasma for their further decoration with PAMAM. • The fabricated three-dimensional (3-D) architecture was employed as the transducer in an impedimetric immunosensor. • An LOD of 0.3 ng/mL of AgIL-10 was obtained. • Detecting AgIL-10 in artificial saliva (AS) as a complex medium was likewise satisfactory. Cytokine storms are known as the uncontrolled overproduction of inflammatory cytokines that can be produced by a variety of viral or non-infectious disorders and inflict significant damage to many organs. Interleukin-10 (IL-10) is an anti-inflammatory cytokine, and rapid detection of its levels in serum and saliva is important for many diseases, including severe COVID-19 patients. In this study, Polystyrene (PS) fibers were electrospun over a gold electrode and modified by air plasma to allow their further decoration with polyamidoamine (PAMAM) dendritic polymer for providing many active sites on the fiber surface. The fabricated three-dimensional (3-D) architecture was employed as a platform in an impedimetric immunosensor for the quantitative detection of interleukin-10 cytokine (AgIL-10). Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), contact angle measurements, fluorescence microscopy, UV–vis spectroscopy, and electrochemical methods including cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to characterized the proposed electrospun fiber-based platform and electrochemical immunosensor. The PAMAM properties increased not only the amperometric response to the ferro/ferri cyanide redox probe, of the modified gold electrode but also the active surface area available for covalently binding of anti-IL-10 capture antibody, resulting in the sensitive detection of AgIL-10 in the concentration range of (1-50 pg/mL) in phosphate buffer saline (PBS) with a limit of detection (LOD) of 1 pg/mL. The immunosensor's performance in detecting AgIL-10 in artificial saliva (AS) as a complex medium was likewise satisfactory. This immunosensor provides a new opportunity for clinical immunoassays thanks to its great sensitivity, selectivity, and stability.