Role of nanocellulose in tailoring electroanalytical performance of hybrid nanocellulose/multiwalled carbon nanotube electrodes

Abstract

Nanocellulose has emerged as a promising green dispersant for carbon nanotubes (CNTs), and there is an increasing trend in developing nanocellulose/CNT hybrid materials for electrochemical detection of various small molecules. However, there have been very few comprehensive studies investigating the role of nanocellulosic material properties upon the electroanalytical performance of the resultant hybrid electrodes. In this work, we demonstrate the influence of both nanocellulose functionalization and geometry, utilizing sulfated cellulose nanocrystals, sulfated cellulose nanofibers, and TEMPO-oxidized cellulose nanofibers. Transmission electron microscopy tomography enables direct visualization of the effect of nanocellulosic materials on the hybrid architectures. High resolution X-ray absorption spectroscopy verifies that the chemical nature of CNTs in the different hybrids is unmodified. Electroanalytical performances of the different nanocellulose/CNT hybrid electrodes are critically evaluated using physiologically relevant biomolecules with different charge such as, dopamine (cationic), paracetamol (neutral), and uric acid (anionic). The hybrid electrode containing fibrillar nanocellulose geometry with a high degree of sulfate group functionalization provides the highest electroanalytical sensitivity and strongest enrichment towards all studied analytes. These results clearly demonstrate for the first time, the extent of tailorability upon the electroanalytical response of nanocellulose/CNT hybrid electrodes towards different biomolecules, offered simply by the choice of nanocellulosic materials.

Protein Adsorption and Its Effects on Electroanalytical Performance of Nanocellulose/Carbon Nanotube Composite Electrodes

“…In contrast, the SCNF/MWCNT composite shows a significantly different redox response toward DA, with a strong oxidation prepeak onset around 0.16 V in both PBS and BSA (Figure c­(i),(ii)). This oxidation prepeak evolution is an indication of oxidation product adsorption on an electrode surface . As has been reported in previous detailed characterizations of the composites, , the surface chemistry of MWCNT remains unaltered in the composites with different nanocellulosic materials.…”

“…This oxidation prepeak evolution is an indication of oxidation product adsorption on an electrode surface . As has been reported in previous detailed characterizations of the composites, , the surface chemistry of MWCNT remains unaltered in the composites with different nanocellulosic materials. Thus, the clear difference observed in DA redox response between the SCNF/MWCNT and SCNC/MWCNT composites can primarily be attributed to morphological differences between the composites, resulting from the nanocellulosic components.…”

“…The nanocellulosic materials and NC/MWCNT composite electrode architectures used in this work have been thoroughly characterized and reported elsewhere in previous works, , and a summary of their different physical and chemical characteristics can be found in Supporting Information (Table S-1). In brief, the SCNF is composed of thread-like and highly sulfated (1.7 mmol/g of OSO 3– groups) fibrils that are ca.…”

“…Use of nanocellulosic materials for the dispersion of carbon nanomaterials provides a promising alternative for the sustainable and economic development of electrochemical sensor platforms and has attracted significant attention in recent years. − The natural abundance of cellulose, along with rapidly developing processing technologies for nanocellulose (NC) extraction and functionalization offer great potential for their use in several fields. , We have recently shown that nanocellulosic materials with varying functionalizations and geometries can be used to successfully develop robust, composite electrochemical platforms with commercial MWCNT, , without the need for any additional modifications to the MWCNTs, which may often decrease electrical conductivity or cause deterioration of their electrochemical properties. − Further, the inherent hygroscopic nature of NC has been shown to have improved biofouling resistance in several applications. , Thus, it is reasonable to expect that the NC composites with MWCNTs would have superior fouling resistance properties, compared to more hydrophobic, purely MWCNT-based architectures. It can also be hypothesized that the nature of the functionalized nanocellulosic component would have a considerable influence on the performance of resultant NC/MWCNT composite in different fouling environments.…”

“… 28 − 30 The natural abundance of cellulose, along with rapidly developing processing technologies for nanocellulose (NC) extraction and functionalization offer great potential for their use in several fields. 31 , 32 We have recently shown that nanocellulosic materials with varying functionalizations and geometries can be used to successfully develop robust, composite electrochemical platforms with commercial MWCNT, 33 , 34 without the need for any additional modifications to the MWCNTs, which may often decrease electrical conductivity or cause deterioration of their electrochemical properties. 35 − 37 Further, the inherent hygroscopic nature of NC has been shown to have improved biofouling resistance in several applications.…”