Multiwalled Carbon Nanotubes/Nanofibrillar Cellulose/Nafion Composite-Modified Tetrahedral Amorphous Carbon Electrodes for Selective Dopamine Detection

Abstract

Vasuki Durairaj) 2 ABSTRACT: We introduce a composite membrane comprising of multi-walled carbon nanotubes (MWCNTs) dispersed in a matrix of sulfated nanofibrillar cellulose (SNFC) and Nafion. The high negative charge densities of the SNFC and Nafion ionomers enhance the cationic selectivity of the composite. The composite is characterized by scanning electron (SEM) and transmission electron (TEM) microscopies as well as Fourier transform infrared (FTIR) and Raman spectroscopies. Tetrahedral amorphous carbon (ta-C) electrodes modified with the composite are investigated as potential dopamine (DA) electrochemical sensors. The composite-modified electrodes show significant selectivity and sensitivity towards DA in the presence of ascorbic acid (AA) and uric acid (UA) in physiologically relevant concentrations. A linear dopamine detection range of 0.05 -100 µM with detection limits of 65 nM in PBS and 107 nM in interferent solution was determined using 100 mV/s cyclic voltammetry (CV) measurements. These results highlight the potential of the composite membrane for in vivo detection of neurotransmitters.

Functionalized Nanocellulose/Multiwalled Carbon Nanotube Composites for Electrochemical Applications

“…The introduction of PEI on the hydrophobic ta-C surface is thus considered to be successful in anchoring the drop-cast nanocellulose/MWCNT membranes, without the need for any additional polymeric binders in the composite, as previously used. 23 Electrochemical measurements in blank electrolyte solutions further verify that the introduction of PEI does not passivate the ta-C substrate (Figure S7). Structural stabilities of the drop-cast electrode membranes were also investigated in deionized water.…”

“…16−22 We have previously demonstrated that the presence of a high density of negatively charged sulfate functional groups on the nanocellulose can significantly improve the selectivity of multiwalled carbon nanotubes (MWCNTs) in the composite electrode, toward the cationic dopamine molecule. 23 The use of such nanocellulose/ nanocarbon composites in electrochemical applications has become increasingly popular in the recent years. 24−30 However, this field is still very much at its early stages, and there is a lack of systematic studies regarding the effects of the nanocellulosic material properties, upon the electrochemical performance of such composites.…”

“…Colloidally stable aqueous dispersions of the cellulosic nanomaterials can be achieved when these surface functional groups possess sufficient ionic charge. − Such functionalized colloidally stable cellulosic nanomaterials can in turn be used to disperse carbon nanomaterials , and further offer tailorable ionic conductivity in the resultant composite matrices. In recent years, several carbon nanomaterials and other two-dimensional (2D) materials have been dispersed in nanocellulosic matrices to obtain functional hybrid nanocomposites for various applications. − We have previously demonstrated that the presence of a high density of negatively charged sulfate functional groups on the nanocellulose can significantly improve the selectivity of multiwalled carbon nanotubes (MWCNTs) in the composite electrode, toward the cationic dopamine molecule . The use of such nanocellulose/nanocarbon composites in electrochemical applications has become increasingly popular in the recent years. − However, this field is still very much at its early stages, and there is a lack of systematic studies regarding the effects of the nanocellulosic material properties, upon the electrochemical performance of such composites.…”

“…The different nanocellulose/MWCNT suspensions are drop-cast on top of tetrahedral amorphous carbon (ta-C) thin-film-coated silicon wafer pieces. ta-C thin films are versatile, chemically inert coatings that can be made using low-cost, patternable, and complementary metal–oxide–semiconductor (CMOS)-compatible, room-temperature deposition process on a variety of substrates. , Modification of the ta-C electrodes with high-surface-area carbon nanomaterials has been shown to significantly improve sensitivity and offer tailorable selectivity toward various small biomolecules for sensing applications. ,− …”

Amorphous Carbon Film with Self‐modified Carbon Nanoparticles Synthesized by Low Temperature Carbonization of Phenolic Resin for Simultaneous Sensing of Dopamine and Uric Acid

“…Interestingly, active materials were employed in modifying supporting to achieve an enhanced and distinguishable chemical signal response. The use of active materials, including carbon balls [29][30], graphene [31][32][33][34], and carbon nanotubes [35] indicate that carbon materials facilitate the electrical analysis signal response of DA and UA [36].…”