Enhanced Sensing of Interleukin 8 by Stripping Voltammetry: Carbon Nanotubes versus Fullerene

The ability to detect protein biomarkers at a subnanomolar level represents a pervasive challenge in order to bring a significant improvement in early diagnosis or progression of pato-physiological processes. To this aim, Screen Printed Electrochemical Sensors have been acquiring a predominant importance. The possibility to use them with different measurement techniques, and to customize their surface to improve the performance represent really attractive features. In this work, performances of two different carbon nanostructures in combination with Stripping Voltammetry were evaluated as tools to improve the detection of Interleukin 8, a cytokine that has pivotal roles in various inflammatory processes and considered as a universal biomarker. Commercially-available Carbon sensors were modified using Carbon Nanotubes and Spherical Fullerene through drop casting technique. Interleukin 8 was quantified using an indirect techniques based on silver stripping catalyzed using Alkaline Phosphatase. The nanostructured sensors showed better sensitivity with sub-nanomolar limit of detection: 0.39 ng/ml for carbon nanotubes and 0.61 ng/ml for fullerene compared to bare carbon electrodes. These modification method is promising for sensitive detection of protein biomarkers in several applications, including the monitoring of inflammatory processes.