Chitosan/genipin modified electrode for voltammetric determination of interleukin-6 as a biomarker of sepsis

Author(s)

Morawski, Franciele de Matos ; Malaquias Dias, Greicy Brisa ; Pereira Sousa, Kelline Alaide ; Formiga, Rodrigo ; Spiller, Fernando ; Parize, Alexandre Luis ; Bafica, Andre ; Jost, Cristiane Luisa

• Document type: Journal article
• Source: International Journal of Biological Macromolecules; v. 224, p. 10-pg., 2022-12-17.

Abstract

Ultrasensitive electroanalytical monitoring of interleukin-6 levels in serum samples has emerged as a valuable tool for the early diagnosis of inflammatory diseases. Despite its advantages, there is a lack of strategies for the label-free voltammetric determination of cytokines. Here, a novel chitosan/genipin modified fluorine tin oxide electrode was developed providing an in-situ hydrogel formation (FTO/CSG). This platform was applied for the detection of interleukin-6, a major pro-inflammatory cytokine. Transmission electron microscopy (TEM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) indicated genipin serves as an efficient green cross-linker to build the immunosensing platform (FTO/CSG/anti-IL-6). EIS showed an increase in charge transfer resistance from 326 to 1360 k omega after the immobilization of anti-IL-6 antibodies. By square wave vol-tammetry, this method achieved a detection limit of 0.03 pg mL-1 with a wide linear range of 0.05-1000 pg mL-1. Additionally, it displayed a high selectivity index when tested in the presence of three inflammatory cytokines as interfering proteins: IL-12, IL-1 beta, and TNF-alpha. The sample matrix effect showed a peak current variation lower than 5 %. The novel method was applied for the quantification of IL-6 in serum samples of septic mice. No statistical differences were observed between the standard ELISA and the proposed method using a confidence level of 95 %. (AU)

• FAPESP's process: 15/50387-4 - Siglec-mediated regulation of neutrophil during sepsis
• Grantee: Fernando de Queiroz Cunha
• Support Opportunities: Regular Research Grants