Structure-property relationships in nanocellulose-based electrochemical sensors

Developing sustainable and eco-friendly electrode materials for electrochemical sensing applications, particularly cellulose-based materials, offers an effective strategy to mitigate environmental contamination while addressing the limitations of fossil-based materials, especially in electroanalytical applications. However, the relationship between the physicochemical properties and electrochemical performance of cellulose-based electrochemical sensors remains poorly understood, even for fundamental electrochemical characteristics. This study introduces a functional, cellulose-derived, carbon-based electrochemical sensor by integrating polyethyleneimine (PEI)/nanocellulose (NC)-based architectures with single-walled carbon nanotube (SWCNT) networks using a layer-by-layer assembly technique. The sensor fabrication incorporates TEMPO-oxidized cellulose nanofibers (TOCNFs), sulfated cellulose nanofibers (SCNFs), and sulfated cellulose nanocrystals (SCNCs). We investigate (i) the detailed physical and chemical properties of SWCNT/PEI/NC sensing platforms and (ii) the correlation between these properties and their electrochemical behavior using both outer-sphere and inner-sphere redox probes. Notably, all fabrication steps are scalable and compatible with potential industrial applications.