Cytokine Detection using Diazonium Modified Gold Microelectrodes Onto Polyimide Substrates with Integrated Ag/AgCl Reference Electrode

Abstract

In this present study, we have analyzed one cytokine biomarker; interleukin-10 (IL-10), which is one of many antigens that is secreted in acute stages of inflammation after left ventricle assisted device (LVAD) implantation for patients suffering from heart failure (HF). Therefore, a biosensor was developed in order to increase the sensitivity of detection, decrease the time of measurements, and to simultaneously detect varying cytokine biomarkers using eight gold working electrodes (WE). This biosensor was fabricated onto a polyimide (PI) substrate using soft lithography technique. The anti-human IL-10 monoclonal antibodies (mAb) were immobilized onto gold microelectrodes through functionalization with carboxyl diazonium. Cyclic voltammetry (CV) was applied during the microelectrode fabrication process to characterize the gold microelectrode surface properties, while, electrochemical impedance spectroscopy (EIS) characterized the diazonium modification made on the gold microelectrodes, followed by the immobilization of IL-10 mAb. Here, a variation of the change transfer resistance (Rct) has confirmed that diazonium has modified the gold microelectrodes and that the mAb was successfully covalently bonded onto the surface.