An integrated flexible dual-mode optical-electrochemical sensing microcatheter platform for inflammation monitoring

Abstract

Timely monitoring of inflammation following transplant surgery is essential to prevent complications such as ischemia or death. Centralized testing often leads to delays. Point-of-care immunoassays offer some promise. However, they lack the form factor and the performance needed for localized monitoring of inflammation. This work demonstrates a novel dual-mode microcatheter platform for in situ quantification of inflammatory biomarkers, such as interleukin- 6 (IL-6). By combining an electrochemical approach, namely differential pulse voltammetry (DPV), and an optical approach, namely localized surface plasmon resonance (LSPR), the platform enables reliable, on-demand, precise monitoring of inflammation. The novelty of the approach is using surgical sutures for electrochemical sensing and its co-integration with an optical fiber for LSPR sensing in a miniaturized and flexible microcatheter platform. This platform can locally probe the surgical or wound site for inflammation monitoring, providing high precision and reliability. The dual-mode approach enhances detection accuracy, precision, and dynamic range. The dual-mode microcatheter sensor exhibited a broad dynamic range from 0.1 to 1000 pg/mL for IL-6 measurement with a limit of detection (LOD) of 0.076 pg/mL for the electrochemical approach and 0.10 pg/mL for the optical LSPR approach. Furthermore, the performance of the dual-mode sensing microcatheter was successfully evaluated in buffer, artificial serum, skin-gel, and human serum samples with co-interferents in the clinical range.