cMWCNT/CoHCF/AuNPs nanocomposites aptasensor for electrochemical detection of interleukin-6

Abstract

In this paper, a novel electrochemical sensing platform for the sensitive detection of interleukin 6 (IL-6) was designed and fabricated. A label-free aptasensor was fabricated by modifying the glassy carbon electrode (GCE) using a nanocomposite composed of carboxylated multi-walled carbon nanotubes (cMWCNTs), cobalt hexacyanoferrate (CoHCF) and gold nanoparticles (AuNPs). The nanocomposite improved electron transfer rate and increased intercalation of signaling molecules. Moreover, it also offers desirable capabilities for the immobilization of biomolecules. The cMWCNTs/CoHCF/AuNPs modified electrode showed good electrochemical characteristics and biocompatibility, thus achieving excellent sensor performance. The differential pulse voltammetry (DPV) was used to detect the peak current of CoHCF in the redox process. The peak current is proportional to the concentration of IL-6 on the electrode surface. Under optimal conditions, the proposed aptamer sensor exhibits a linear range from 0.5 pg/mL to 1000 pg/mL and has a low detection limit of 0.17 pg/mL. In addition, the IL-6 aptamer sensor has good selectivity, high stability, and satisfactory reproducibility, showing broad potential in clinical research and diagnostic applications.

Keywords

• Unlabeled aptamer sensor
• Cobalt hexacyanoferrate
• Gold nanoparticles
• Multi-walled carbon nanotubes
• Electrochemical detection
• Interleukin-6 (IL-6)