Multiplex on-chip immunosensor for advancing inflammation biomarkers monitoring

Abstract

Chronic inflammatory diseases significantly impact quality of life and healthcare resources. Continuous monitoring of biomarkers in easily accessible biological fluids presents a promising strategy to enhance management, optimize treatments, and improve patient outcomes. Interleukin-8 (IL-8) is a pro-inflammatory cytokine whose levels increase during chronic airways inflammatory diseases and can be found in human saliva. To this end, electrochemical immunosensors which can effectively detect clinically relevant biomarkers, while also offering the benefits of miniaturization and portability will enable telemedicine applications for remote monitoring and personalized healthcare. In this work, we developed an advanced electrochemical multiplex immunosensor platform using gold micro-electrodes modified by the electrochemical deposition of a gold foam and an antifouling polymeric layer. The sensor capability for multiple detection was evaluated by measuring human interleukin 8 (H-IL8) and human immunoglobulin G (H-IgG) (the latter used as a model analyte). Immunosensors exhibited high sensitivity even in complex biological samples such as human serum and artificial saliva. A very low detection limit of 69.2 fg mL⁻¹ for H-IgG and 87.6 fg mL⁻¹ for H-IL8 in phosphate buffered saline was established. To assess real-world applicability, the immunosensor was used to quantify H-IL8 release from primary human monocyte-derived macrophages stimulated with pro-inflammatory bacterial lipopolysaccharide and the results were successfully compared with ELISA. Furthermore, the sensor performance was also demonstrated in real biological fluids by detecting H-IL8 in spiked human saliva.