A Robust Strategy Enabling Addressable Porous 3D Carbon-based Functional Nanomaterials in Miniaturized Systems
TL;DR: It is shown here that 3D-carbon nanofibrous electrodes of various designs, shapes and sizes, on flexible substrates, under ambient conditions and without complicated equipment and procedures can be "written" via a one-step laser-induced carbonization on electrospun nan ofibers.
Abstract: 3D-porous carbon nanomaterials and their hybrids are ideal materials for energy storage and conversion, biomedical research, and wearable sensors, yet today's fabrication methods are too complicated and inefficient to implement into miniaturized systems. Instead, it is shown here that 3D-carbon nanofibrous electrodes of various designs, shapes and sizes, on flexible substrates, under ambient conditions and without complicated equipment and procedures can simply be "written" via a one-step laser-induced carbonization on electrospun nanofibers. Analytical functionalities are realized as full control over native polymer chemistry doping of the polymer (e.g. with metals) is provided. Similarly, being able to control mat morphology and its impact on the electroanalytical performance was studied. Ultimately, optimized writing conditions were harnessed for superior (bio)analytical sensing of important biomarkers (NADH, dopamine). The new procedure hence paves the way for future controlled studies on this 3D nanomaterial, for a multitude of functionalization and design possibilities, and for mass production capabilities necessary for their application in the real world.
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01 Mar 2013
TL;DR: Electrospun Carbon Nanofiber Webs with Controlled Density of States for Sensor Applications by Xianwen Mao, Fritz Simeon, Gregory C. Rutledge, and T. Alan Hatton.
Abstract: 1 DOI: 10.1002/adma.((please add manuscript number)) Electrospun Carbon Nanofiber Webs with Controlled Density of States for Sensor Applications By Xianwen Mao, Fritz Simeon, Gregory C. Rutledge* and T. Alan Hatton* [*] Prof. T. Alan Hatton, Prof. Gregory C. Rutledge, Xianwen Mao, Dr. Fritz Simeon. Department of Chemical Engineering, Massachusetts Institute of Technology 77 Massachusetts Avenue, Cambridge Massachusetts, 02139, USA E-mail: tahatton@mit.edu, rutledge@mit.edu
76 citations
TL;DR: It is demonstrated that LIG facilitates all three electrochemical sensing strategies (voltammetry, potentiometry, impedance) in a multi-analyte system for sweat analysis and has the potential to outcompete standard screen-printed electrodes.
Abstract: Multi-analyte sensing using exclusively laser-induced graphene (LIG)-based planar electrode systems was developed for sweat analysis. LIG provides 3D structures of graphene, can be manufactured easier than any other carbon electrode also on large scale, and in form of electrodes: hence, it is predestinated for affordable, wearable point-of-care sensors. Here, it is demonstrated that LIG facilitates all three electrochemical sensing strategies (voltammetry, potentiometry, impedance) in a multi-analyte system for sweat analysis. A potentiometric potassium-ion-selective electrode in combination with an electrodeposited Ag/AgCl reference electrode (RE) enabled the detection of potassium ions in the entire physiologically relevant range (1 to 500 mM) with a fast response time, unaffected by the presence of main interfering ions and sweat-collecting materials. A kidney-shaped interdigitated LIG electrode enabled the determination of the overall electrolyte concentration by electrochemical impedance spectroscopy at a fixed frequency. Enzyme-based strategies with amperometric detection share a common RE and were realized with Prussian blue as electron mediator and biocompatible chitosan for enzyme immobilization and protection of the electrode. Using glucose and lactate oxidases, lower limits of detection of 13.7 ± 0.5 μM for glucose and 28 ± 3 μM for lactate were obtained, respectively. The sensor showed a good performance at different pH, with sweat-collecting tissues, on a model skin system and furthermore in synthetic sweat as well as in artificial tear fluid. Response time for each analytical cycle totals 75 s, and hence allows a quasi-continuous and simultaneous monitoring of all analytes. This multi-analyte all-LIG system is therefore a practical, versatile, and most simple strategy for point-of-care applications and has the potential to outcompete standard screen-printed electrodes.
26 citations
TL;DR: This work demonstrates that Ni-nanoparticles embedded in 3D CNFs of any shape and design can be easily prepared using electrospinning followed by laser carbonization under ambient conditions and adapted to a whole range of metal precursors.
Abstract: Carbon nanofiber (CNF) nanocatalyst hybrids hold great promise in fields such as energy storage, synthetic chemistry, and sensors. Current strategies to generate such hybrids are laborious and utterly incompatible with miniaturization and large-scale production. Instead, this work demonstrates that Ni nanoparticles embedded in three-dimensional (3D) CNFs of any shape and design can be easily prepared using electrospinning, followed by laser carbonization under ambient conditions. Specifically, a solution of nickel acetylacetonate /polyimide is electrospun and subsequently a design is printed via CO2 laser (Ni-laser-induced carbon nanofiber (LCNFs)). This creates uniformly distributed small Ni nanoparticles (∼8 nm) very tightly adhered to the CNF network. Morphological and performance characteristics can be directly influenced by metal content and lasing power and hence adapted for the desired application. Here, Ni-LCNFs are optimized for nonenzymatic electrochemical sensing of glucose with great sensitivity of 2092 μA mM-1 cm-2 and a detection limit down to 0.3 μM. Its selectivity for glucose vs interfering species (ascorbic and uric acid) is essentially governed by the Ni content. Most importantly, this strategy can be adapted to a whole range of metal precursors and hence provide opportunities for such 3D CNF-nanocatalyst hybrids in point-of-care applications where high-performance but also sustainable and low-cost fabrications are of utmost importance.
19 citations
TL;DR: In this article, the authors evaluate the current strategies to create such nanomaterials to serve as non-enzymatic transducers and evaluate their performance in terms of low cost, good electrical conductivity, and stability.
Abstract: Non-enzymatic electrochemical sensors possess superior stability and affordability in comparison to natural enzyme-based counterparts. A large variety of nanomaterials have been introduced as enzyme mimicking with appreciable sensitivity and detection limit for various analytes of which glucose and H2O2 have been mostly investigated. The nanomaterials made from noble metal, non-noble metal, and metal composites, as well as carbon and their derivatives in various architectures, have been extensively proposed over the past years. Three-dimensional (3D) transducers especially realized from the hybrids of carbon nanomaterials either with metal-based nanocatalysts or heteroatom dopants are favorable owing to low cost, good electrical conductivity, and stability. In this critical review, we evaluate the current strategies to create such nanomaterials to serve as non-enzymatic transducers. Laser writing has emerged as a powerful tool for the next generation of devices owing to their low cost and resultant remarkable performance that are highly attractive to non-enzymatic transducers. So far, only few works have been reported, but in the coming years, more and more research on this topic is foreseeable.
15 citations
TL;DR: In this paper , the authors explored the recent advancements in photocatalytic hydrogen (H2) production utilizing carbon-based nanomaterials (CNMs) and showed that carbon quantum dot (CQD)-sensitized titanium dioxide (TiO2) can demonstrate to have a hydrogen generation activity of 472 mol g−1 h−1 and 1458 mol g −1 h −1 without and with loading metal co-catalyst (Pt).
2 citations
References
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TL;DR: The graphene edge showed 4 orders of magnitude higher specific capacitance, much faster electron transfer rate and stronger electrocatalytic activity than those of graphene basal plane, making it an ideal electrode for electrocatalysis and for the storage of capacitive charges.
Abstract: Graphene has a unique atom-thick two-dimensional structure and excellent properties, making it attractive for a variety of electrochemical applications, including electrosynthesis, electrochemical sensors or electrocatalysis, and energy conversion and storage. However, the electrochemistry of single-layer graphene has not yet been well understood, possibly due to the technical difficulties in handling individual graphene sheet. Here, we report the electrochemical behavior at single-layer graphene-based electrodes, comparing the basal plane of graphene to its edge. The graphene edge showed 4 orders of magnitude higher specific capacitance, much faster electron transfer rate and stronger electrocatalytic activity than those of graphene basal plane. A convergent diffusion effect was observed at the sub-nanometer thick graphene edge-electrode to accelerate the electrochemical reactions. Coupling with the high conductivity of a high-quality graphene basal plane, graphene edge is an ideal electrode for electrocatalysis and for the storage of capacitive charges.
436 citations
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29 Nov 2020TL;DR: The ease of formation of LIG, its simple scale-up, and its utility for a range of applications highlights the easy transition of this substrate-bound graphene foam into commercial device platforms.
Abstract: ConspectusResearch on graphene abounds, from fundamental science to device applications. In pursuit of complementary morphologies, formation of graphene foams is often preferred over the native two-dimensional (2D) forms due to the higher available area. Graphene foams have been successfully prepared by several routes including chemical vapor deposition (CVD) methods and by wet-chemical approaches. For these methods, one often needs either high temperature furnaces and highly pure gases or large amounts of strong acids and oxidants. In 2014, using a commercial laser scribing system as found in most machine shops, a direct lasing of polyimide (PI) plastic films in the air converted the PI into 3D porous graphene, a material termed laser-induced graphene (LIG). This is a one-step method without the need for high-temperature reaction conditions, solvent, or subsequent treatments, and it affords graphene with many five-and seven-membered rings. With such an atomic arrangement, one might call LIG “kinetic grap...
323 citations
TL;DR: It is demonstrated that three-dimensional, macroporous, highly conductive, and monolithic graphene foam synthesized by chemical vapor deposition represents a novel architecture for electrochemical electrodes and envision that the graphene foam provides a promising platform for the development of electrochemical sensors as well as other applications, such as energy storage and conversion.
Abstract: Graphene, a single-atom-thick monolayer of sp(2) carbon atoms perfectly arranged in a honeycomb lattice, is an emerging sensing material because of its extraordinary properties, such as exceptionally high specific surface area, electrical conductivity, and electrochemical potential window. In this study, we demonstrate that three-dimensional (3D), macroporous, highly conductive, and monolithic graphene foam synthesized by chemical vapor deposition represents a novel architecture for electrochemical electrodes. Being employed as an electrochemical sensor for detection of dopamine, 3D graphene electrode exhibits remarkable sensitivity (619.6 μA mM(-1) cm(-2)) and lower detection limit (25 nM at a signal-to-noise ratio of 5.6), with linear response up to ∼25 μM. And the oxidation peak of dopamine can be easily distinguished from that of uric acid - a common interferent to dopamine detection. We envision that the graphene foam provides a promising platform for the development of electrochemical sensors as well as other applications, such as energy storage and conversion.
297 citations
TL;DR: In this paper, Palladium nanoparticle-loaded carbon nanofibers (Pd/CNFs) were synthesized by the combination of electrospinning and thermal treatment processes.
Abstract: Palladium nanoparticle-loaded carbon nanofibers (Pd/CNFs) were synthesized by the combination of electrospinning and thermal treatment processes. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images show that spherical Pd nanoparticles (NPs) are well-dispersed on the surfaces of CNFs or embedded in CNFs. X-ray diffraction (XRD) pattern indicates that cubic phase of Pd was formed during the reduction and carbonization processes, and the presence of Pd NPs promoted the graphitization of CNFs. This nanocomposite material exhibited high electric conductivity and accelerated the electron transfer, as verified by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The Pd/CNF-modified carbon paste electrode (Pd/CNF-CPE) demonstrated direct and mediatorless responses to H2O2 and NADH at low potentials. The analytical performances of the Pd/CNF-CPEs towards reduction of H2O2 and oxidation of NADH were evaluated. The high sensitivity, wider linear range, good reproducibility, and the minimal surface fouling make this Pd/CNF-CPE a promising candidate for amperometric H2O2 or NADH sensor.
289 citations
TL;DR: In this paper, a carbon nanotube (CNT) surface was successfully modified using the UV/Ozone treatment and a triethylenetetramine (TETA) solution for use as the reinforcement for polymer matrix composites.
282 citations