CNT Surface Research Articles

Preparation and Characterization of Graphene Oxide/Carbon Nanotube/Polyaniline Composite and Conductive and Anticorrosive Properties of Its Waterborne Epoxy Composite Coatings.

The organic coating on the surface is common and the most effective method to prevent metal materials from corrosion. However, the corrosive medium can penetrate the metal surface via micropores, and electrons cannot transfer in the pure resin coatings. In this paper, a new type of anticorrosive and electrically conductive composite coating filled with graphene oxide/carbon nanotube/polyaniline (GO/CNT/PANI) nanocomposites was successfully prepared by in situ polymerization of aniline (AN) on the surface of GO and CNT and using waterborne epoxy resin (WEP) as film-forming material. The structure and morphology of the composite were characterized using a series of characterization methods. The composite coatings were comparatively examined through resistivity, potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS), and salt spray tests. The results show that the GO/CNT/PANI/WEP composite coating exhibits excellent corrosion resistance for metal substrates and good conductivity when the mass fraction of GO/CNT/PANI is 3.5%. It exhibits a lower corrosion current density of 4.53 × 10-8 A·cm-2 and a higher electrochemical impedance of 3.84 × 106 Ω·cm2, while only slight corrosion occurred after 480 h in the salt spray test. The resistivity of composite coating is as low as 2.3 × 104 Ω·cm. The composite coating possesses anticorrosive and electrically conductive properties based on the synergistic effect of nanofillers and expands the application scope in grounding grids and oil storage tank protection fields.

Structural Analysis and Electrical Property of Acid‐Treated MWCNT

ABSTRACTThe electrical properties of acid‐treated CNT were investigated in terms of functional group and microstructure. A mixture of HNO3 and H2SO4 was used to acid treatment of CNT, and acid‐treated CNTs were synthesized by the mixture for 0 to 5 h. In crystal structure analysis, as acid treatment time was increased, the intensity of graphite diffraction peak was decreased and shifted to lower angle. It indicates a decrease in the crystallinity of CNT surface and lattice contraction by loss of carbon atoms. The distribution of oxygen on CNT surface was observed by TEM analysis confirming that functional groups and structural defects were formed. ID/IG ratio and average distance between defects (LD) were calculated using Raman spectroscopy to analyze the structural characteristics of CNT, and the greatest decrease was identified from p‐CNT to 2h‐CNT, resulting in the formation of functional groups and the changes in structural defects on CNT surface by acid treatment in the initial stage. Bonding state on CNT surface was analyzed through XPS analysis, and functional groups such as CO and COH were confirmed in acid‐treated CNT. Sheet resistance was measured to analyze the electrical properties of CNT, and 3h‐CNT showed the lowest sheet resistance at 25.28 Ω.

Mechanism simulation of polar and nonpolar organic solvent vapor adsorption on a multiwall carbon nanotubes paper gas sensor.

We investigate the adsorption behavior of polar and nonpolar molecules on carbon nanotube interfaces through computational simulations. Gaussian 16 was utilized to calculate the total energy of each possible molecular structure and analyze the adsorption mechanisms in stacked and inline configurations. The study reveals that nonpolar molecules favor stacked adsorption on two graphene interfaces, while polar molecules prefer inline adsorption. The findings suggest that inline adsorption of polar molecules results in minimal changes to the local dielectric constant, which may explain the absence of multi-step adsorption isotherms. The research examines the stability and energetics of molecular adsorption on graphene layers simulating CNT interfaces. Different types of molecules (polar and nonpolar) exhibit distinct adsorption behaviors, with nonpolar molecules aligning with the IUPAC type VI isotherm model and polar molecules following the Langmuir isotherm model (IUPAC type I). This study provides insight into how molecules are likely to adsorb on CNT surfaces and the impact on the local dielectric constant. This understanding has implications for the design and optimization of CNT-based sensors, particularly in detecting organic solvents and gases in various environments.

The effect of gamma-ray irradiation on polymer-graphene nanocomposite interfaces

CNT yarns are used in ultra-high strength composites for use in manned deep-space vehicles. It has been previously demonstrated through experiments that gamma-ray irradiation substantially improves the mechanical performance of these composites. It is unclear how the irradiation affects the mechanical response of the CNT yarn/polymer interface that ultimately leads to these panel-level performance improvements. Physical insight into this process could enable further improvements in the CNT yarn/polymer interface design in the future. The objective of this research is to use molecular dynamics simulation to provide physical insight into the effect of gamma-ray irradiation on the mechanical behavior (interfacial interaction energy, shear resistance, adhesive strength) of the CNT yarn/polymer interface for a range of high-performance polymer systems. The simulation results indicate that gamma-ray irradiation (simulated via inclusion of defects on the CNT surface) has a most significant effect on the shear deformation resistance of CNT yarn/polymer interfaces, which likely leads to the experimentally-observed improvements in panel-level CNT yarn composites irradiated with gamma rays. The results of this study also demonstrate the importance of computational modeling in providing physical insight into observed bulk-scale material behavior. Although the predictions cannot be validated directly via experiment, such insight can ultimately lead to efficient improvements in material design (e.g. mechanical performance) that lead to further increases in panel-level composite performance.

CNT@SrTiO3 Nanocomposites Synthesized by In Situ Reaction for a High-Performance Flexible Supercapacitor.

This study presents the in situ synthesis of CNT@SrTiO3 nanocomposite films for the development of high-performance flexible supercapacitors. The synthesis process involved the use of organic-inorganic hybrid polymers containing metal elements as precursors for thermal decomposition reaction under a reducing atmosphere. Due to the formation of chemical bonding between Ti elements and the CNTs, the interface between STO and CNT surface could provide additional active sites for ion transport and storage. Thereby, the incorporation of SrTiO3 nanoparticles into CNTs enhanced the electrochemical performance of the resulting nanocomposite membranes. To further investigate the influence of STO content and synthesis temperature, we conducted a detailed analysis. The findings indicated that the CNT@STO film with 25% STO content, synthesized at 700 °C, and possessed optimal performance with an areal capacitance of 6682 mF·cm-2 at 5 mV·s-1. Furthermore, a symmetrical flexible supercapacitor assembled by two CNT@STO-25 electrodes demonstrated strong application potential in wearable devices, owing to its long cycle life, excellent flexibility, and high energy density of 430.2 μWh·cm-2 (corresponding power density of 4.5 mW·cm-2). Based on these results, we believe that this study provides a fresh idea for the development of novel flexible energy storage materials.

Quantum-chemical modeling of sorption interactions of histidine enantiomers with carbon nanotubes

In this study, the elementary act of adsorption of monomers and dimers of histidine enantiomers on a dextrorotatory model CNT-(7,6) chirality from an aqueous solution was studied using quantum chemistry methods to interpret the adsorption isotherm of L- and D-histidine on carbon nanotubes mkNANO MKN-SWCNT S1 and identify the mechanism of sorption sorbent-sorbate interactions. Quantum chemical modelling of the structures was carried out using the GAUSSIAN 09 program by the B3LYP/6-31G(d,p) GD3 method; the influence of the environment was considered using the Tomasi polarization continuum model (PCM). The results of quantum chemical modelling have established a greater number of point interactions of nitrogen and oxygen atoms of the D-isomer with the dextrorotatory CNT, which determines the higher adsorption energy of the D-histidine monomer and dimer on the CNT compared to the L-isomer. It was shown that enantiomers are attached to nanotubes mainly by van der Waals forces and π-π interactions between the imidazole ring of histidine and the carbon nanotube. The contribution of π-π stacking interactions to the adsorption value was assessed using quantum chemistry methods. The formation of 4 different L-amino acid dimers is possible on the surface of CNT: 2L1, 2L2, 2L3, 2L4 and also for the D isomer: 2D1; 2D2; 2D3; 2D4. The results of quantum chemical modelling showed that dimers 2L4 and 2D4 have the highest adsorption energy on CNT. Quantum chemistry methods were also used to calculate the average energy of intermolecular H bonds in seven, eight, and thirteen particle clusters of L-histidine, as well as in seven- and nine-particle clusters of the D-enantiomer. The calculation showed that this value increases with increasing cluster size. This led to a significant contribution of hydrogen bonding to the decrease in the energy of the sorption system during cluster adsorption.

Ionic liquid in-situ functionalized carbon nanotube film as self-supported metal-free electrocatalysts for oxygen evolution

The oxygen evolution reaction (OER) is a critical cathode reaction for hydrogen production from water splitting. However, due to the sluggish kinetics of OER, the water-splitting process is impeded. Thus, it is imperative to develop efficient and low-cost electrocatalysts that reduce the overpotential and improve the kinetics of OER. Herein, an in-situ synthesis strategy was applied to prepare the ionic liquid functionalized carbon nanotube (IL-CNT) that served as a metal-free electrocatalyst for OER. This powder material exhibited exceptional electrocatalytic activity for OER, with an overpotential of 335 mV at 10 mA cm−2 and a Tafel slope of 71 mV dec-1. Then, it was found that catalytic activity was influenced by the IL anion. Moreover, this IL-CNT powder could self-assemble to form carbon film during preparation, exhibiting outstanding catalytic activity for OER (a low overpotential of 153 mV at 10 mA cm−2), which was highly beneficial for practical application. Based on the theoretical calculations and experimental results, these in-situ functionalization sites on CNT surface played a significant role in regulating their electron structure. This, in turn, promoted electron transfer and hydroxyl adsorption, resulting in a substantial increase in catalytic activity for the OER.

Comparison Between Wet and Dry Transfer Fe2O3-CNT Hybrid Thin Films as Room-Temperature Liquefied Petroleum Gas (LPG) Sensors

Fe2O3-CNT hybrid thin films are promising candidates for room-temperature gas sensors with high sensitivity, rapid response, and recovery times. In this work, we reported the suitable fabrication strategies of Fe2O3-CNT hybrid thin films as liquefied petroleum gas (LPG) sensors by comparing the dry (without using aqueous solutions) and wet processes. Fe-CNT hybrid thin films were used as the primary material for synthesizing Fe2O3-CNT hybrid thin films, which were then annealed in air at 350oC to create α-Fe2O3. Characterizations by X-ray photoelectron spectroscopy, transmission electron microscopy, and field emission scanning electron microscopy (FE-SEM) confirmed the decoration of α- Fe2O3 nanoparticles on CNT surfaces. The transfer process had effects on the surface morphology and sensor characteristics. FE-SEM presents that the surface morphology of the wet-transfer Fe2O3-CNT films was web-like structures with a highly porous morphology. Whereas the surface morphology of the dry-transferred Fe2O3-CNT films was a branch-like structure. The I-V relationship of both annealed wet- and dry- films was non-linear indicating the present of n-type α- Fe2O3. Under 5 vol.% of LPG, the wet-transferred Fe2O3- CNT films have higher sensitivity (S = ~ 3% Tresp.= 10 s, trec.= 59s) compared to the dry- transferred Fe2O3-CNT films (S = ~ 1.4%, Tresp.=90s, trec.= incomplete recovery). Moreover, the wet-transferred Fe2O3-CNTs could detect LPG concentration at a lower value than 25% of LEL (Lower Explosive Limit) with rapid response and recovery time of 23 s and 49 s, respectively.

Novel covalent organic framework/carbon nanotube composites with multiple redox-active sites for high-performance Na storage

Covalent organic frameworks (COFs) have attracted great attention as promising energy storage materials due to their exceptional crystallinity, designable periodic skeletons, adjustable porous distribution, and ordered accessible nano-channels. However, the reported COF-based cathodes are hindered by unsatisfying capacity and limited rate performance because of their limited utilization of redox-active groups and poorer electrical conductivity. Herein, a novel TP-OH-COF with rich redox-active groups integrated with carbon nanotube (TP-OH-COF@CNT50) is prepared in a one in-situ polycondensation. The few-layered TP-OH-COF with abundant active groups (CO) wrapped on the surface of CNT can accommodate more Na-ions and shorten the ion/electron diffusion distance. As a sodium-ion batteries (SIBs) cathode, the TP-OH-COF@CNT50 delivers a high specific capacity of 256.4 mAh g−1 at 0.1 A g−1, ultra-long cycling stability (100 % retention after 3000 cycles at 2 A g−1), and excellent rate performance (103 mAh g−1 at 10 A g−1). The combination of in (ex) situ experiments manifests the high reversible surface-dominated Na-storage mechanism and structural stability with lower energy barrier for Na-ions diffusion in TP-OH-COF@CNT50 during Na-ions insertion/extraction. The theoretical calculations unveil the reaction sites and processes of Na-ions storage in TP-OH-COF@CNT50. The results provide an effective strategy for designing new COFs with high energy storage for SIBs.

Impact of Fe3O4-CNT Hybrid with Magnetic Field Control on Corrosion Resistance of Inorganic Phosphate Bonded Coating

Fe3O4-CNT nanomaterials were used to enhance the corrosion performance of inorganic phosphate bonded coatings (IPBCs). Firstly, Fe3O4-CNT nanomaterials were prepared through hydrothermal method and characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscope (SEM). The results show that Fe3O4 nanoparticles relatively evenly distributed on the surface of CNT. Then, Fe3O4-CNT hybrids were added into IPBC as the reinforcing phase, IPBC, IPBC reinforced by Fe3O4-CNT hybrids (IPBC-CNT) and IPBC reinforced by Fe3O4-CNT hybrids with magnetic field control (IPBC-CNT-Mag) were prepared, respectively. And the corrosion performance of the three coatings were analyzed through open circuit potential, polarization curves and electrochemical impedance spectrum (EIS) experiments. Results shows the protection efficiency of neat IPBC, IPBC-CNT and IPBC-CNT-Mag is around 80.30, 94.98, 95.64%, indicating adding Fe3O4-CNT nanomaterials as a functional filler to the inorganic phosphate bonded coating can effectively enhance the corrosion resistance of the coating, while Fe3O4-CNT hybrids after magnetic field treatment can further improve the corrosion resistance of IPBCs. That is because with the introduction of magnetic field, Fe3O4-CNT hybrid can be better dispersed in IPBC, so that CNT can be better utilized and played, which resulting the excellent corrosion performance of IPBC-CNT-Mag.

Active Sites of Cobalt Phthalocyanine in Electrocatalytic CO2 Reduction to Methanol.

Many metal coordination compounds catalyze CO2 electroreduction to CO, but cobalt phthalocyanine hybridized with conductive carbon such as carbon nanotubes is currently the only one that can generate methanol. The underlying structure-reactivity correlation and reaction mechanism desperately demand elucidation. Here we report the first in situ X-ray absorption spectroscopy characterization, combined with ex situ spectroscopic and electrocatalytic measurements, to study CoPc-catalyzed CO2 reduction to methanol. Molecular dispersion of CoPc on CNT surfaces, as evidenced by the observed electronic interaction between the two, is crucial to fast electron transfer to the active sites and multi-electron CO2 reduction. CO, the key intermediate in the CO2 -to-methanol pathway, is found to be labile on the active site, which necessitates a high local concentration in the microenvironment to compete with CO2 for active sites and promote methanol production. A comparison of the electrocatalytic performance of structurally related porphyrins indicates that the bridging aza-N atoms of the Pc macrocycle are critical components of the CoPc active site that produces methanol. In situ X-ray absorption spectroscopy identifies the active site as Co(I) and supports an increasingly non-centrosymmetric Co coordination environment at negative applied potential, likely due to the formation of a Co-CO adduct during the catalysis.

Active Sites of Cobalt Phthalocyanine in Electrocatalytic CO2 Reduction to Methanol

AbstractMany metal coordination compounds catalyze CO2 electroreduction to CO, but cobalt phthalocyanine hybridized with conductive carbon such as carbon nanotubes is currently the only one that can generate methanol. The underlying structure–reactivity correlation and reaction mechanism desperately demand elucidation. Here we report the first in situ X‐ray absorption spectroscopy characterization, combined with ex situ spectroscopic and electrocatalytic measurements, to study CoPc‐catalyzed CO2 reduction to methanol. Molecular dispersion of CoPc on CNT surfaces, as evidenced by the observed electronic interaction between the two, is crucial to fast electron transfer to the active sites and multi‐electron CO2 reduction. CO, the key intermediate in the CO2‐to‐methanol pathway, is found to be labile on the active site, which necessitates a high local concentration in the microenvironment to compete with CO2 for active sites and promote methanol production. A comparison of the electrocatalytic performance of structurally related porphyrins indicates that the bridging aza‐N atoms of the Pc macrocycle are critical components of the CoPc active site that produces methanol. In situ X‐ray absorption spectroscopy identifies the active site as Co(I) and supports an increasingly non‐centrosymmetric Co coordination environment at negative applied potential, likely due to the formation of a Co−CO adduct during the catalysis.

Effect of the bare and functionalized single-wall carbon nanotubes on inhibition of asphaltene molecules aggregation: A molecular dynamic simulation

A comprehensive study has been carried out by utilizing the molecular dynamics technique in order to investigate the behavior of the N-(1-hexylheptyl)-N'-(2-phenylpropanoicacid)-perylene-3,4,9,10-tetracarboxylicbisimide (PAP) molecules in the n-heptane/toluene solution as well as the role of the bare and functionalized single-wall carbon nanotubes (SWCNTs) with the carboxyl groups (-COOH) on the aggregation of PAP molecules. It was found that the CNTs benefit two mechanism of steric hindrance and adsorbing the PAP molecules to suppress the affinity of PAP molecules to association. The results ascertain that the constant amount of the carboxyl groups acts more efficiently in restricting the growth of aggregate size if they are distributed on the surface of a larger CNT. Both of the increased nonbonding interactions between the functionalized CNTs and the PAP molecules, and the number of formed hydrogen bonds between them clearly proved the efficiency of the –COOH groups in improving the stability of PAP molecules. The strength of the adsorption free energies revealed that the PAP molecule shows more tendency to be adsorbed on the surface of CNT modified with carboxyl groups. Increasing the dosage of the –COOH groups on the surface of the CNTs with constant dimension causes an increment in the PAP molecules' solvent accessible surface area (SASA) value, indicating enhanced stability of the PAP molecules. Finally, the results would facilitate future studies on manipulating the asphaltene precipitation in the oil industry.

Synergistic effect of bimodal structure and Cu-coated CNTs on the properties of Cu/CNTs composites

Multi-walled carbon nanotube-reinforced Cu matrix composites (Cu/MCNTs) present a challenge in achieving high strength and good ductility. To address this issue, the bimodal structure composites were fabricated by vacuum mixing of coarse Cu powder (Cum) and fine Cu powder along with Cu-coated CNTs (CCNTs) followed by spark plasma sintering (SPS). Two sets of bimodal composites with 1 wt% Cu-coated CNTs were fabricated by varying the proportion of fine to coarse Cu powder (70:30 and 30:70). The unimodal composite was prepared by mixing Cum and 1 wt% functionalized CNTs in a ball mill for 1 h followed by SPS. Using electron backscatter diffraction (EBSD), the microstructure of the prepared composites was examined, and the influence of coarse grain and fine grain, along with CCNTs, on the structure-property correlation in the composites was investigated. The results show that the bimodal composites outperform the unimodal counterpart, and the bimodal composite with fine to coarse Cu grain ratio of 70:30 has the highest compressive strength (323 MPa), compressive strain (18.8%) electrical conductivity (85.4 ± 0.6% IACS), and thermal conductivity (295.4 ± 5 W/mK). The increase in strength of the bimodal composite is attributed to the Cu-coated CNTs and the tuning between coarse and fine grain. Load transfer, aided by the Cu coating on the CNT surface, is revealed to be the primary strengthening mechanism for bimodal composites. This work sheds light on the mechanisms of strengthening and the structure-property correlations in bimodal composites.

One-pot synthesis of a CdS–MoS2 / CNTs nano-composite for photocatalytic hydrogen production under visible light

The need to meet growing energy demands of global society in a sustainable fashion requires the development of techniques and processes to reduce dependence on fossil fuels and transit to renewable energy sources. Environmentally benign technologies for alternative fuel production in the form of hydrogen can be developed via heterogenous photocatalysis, a process based on utilization of solar energy. To this end, a cadmium sulfide (CdS) based photocatalyst was developed, doped with MoS2 in a one-pot solvothermal synthesis technique, and coupled with multi-walled carbon nanotubes (MWCNTs) as a carbonaceous support. The material exhibiting the highest rate of hydrogen evolution, CM5C3, involved a MWCNTs loading of 3% and MoS2 loading of 5%. Compared to pure CdS synthesized with the same adapted procedure, the 3% CNT loading improved the rate of hydrogen production by nearly 7-fold, and the optimal 5% MoS2 loading further improved the performance by 60%. CM5C3, achieved an apparent quantum efficiency of 7.34%, a 26-fold increase compared to pure CdS. FESEM and HRTEM imaging confirmed the nanorod-like growth of CdS–MoS2 on the CNT surface, with elemental mapping confirming homogenous dispersion of MoS2 and CNTs. In addition, lattice fringe spacings indicated the presence of cubic and hexagonal CdS growing predominantly along the (111) and (002) planes respectively, in addition to MoS2 distributed throughout the crystal lattice. XRD analysis confirmed the presence of hexagonal and cubic CdS, however, MoS2 phases were not registered perhaps due to the low concentration present in the bulk of the material. XPS survey scans showed the presence of C, Cd, Mo, and S only, with trace oxygen impurities. Peak deconvolution indicated the presence of characteristic peaks for CdS and MoS2, in addition to evidence of the presence of Cd–C bonds, indicating strong CdS heterojunctions to the CNT surface.

Adsorption of Albumin Fragments on Crystalline SWCNTs: How Surface Curvature Can Affect Protein Secondary Structure

AbstractProtein adsorption on biomaterial surfaces is a crucial step for biocompatibility. Albumin is the most abundant blood protein, and then this protein is important for biomaterials that will come into contact with blood. In previous work a theoretical study based on molecular mechanics (MM) and molecular dynamics (MD) methods is carried out at atomistic level to investigate the adsorption process of albumin A‐subdomain on graphite surface and single‐walled carbon nanotubes (SWCNTs) having different curvature. The aim of this work is to study the adsorption process of the albumin A‐subdomain on four (10,10) SWCNTs in a crystalline arrangement in order to understand how the curvature of ordered nanotubes affects the adsorption process, providing also a simplified model of a rough surface at the nanometer level of a small crystalline domain. Interestingly, this soft albumin fragment having three α‐helices in the native state, yields a short β‐sheets arrangement during the MD run. This finding suggests the importance not only of the rigidity of protein but also the curvature of the surface which can induce a secondary structure other than the native one. This theoretical work can be useful for investigating aspects that influence the conformation, then both the functionality of proteins adsorbed on CNT surfaces and their biocompatibility, and the favorable interactions interesting for NT solubilization to prepare reinforced composite materials.

Anticorrosion mechanism of ethylene-chlorotrifluoroeethylene coatings reinforced with hydroxylated carbon nanotubes: An experimental and molecular dynamics simulation study

Carbon nanotubes/ethylene-chlorotrifluoroeethylene (CNT/ECTFE) composite coatings were prepared on the surface of carbon steel via electrostatic spraying and low temperature heat treatment. The influence of hydroxylated carbon nanotubes on the anticorrosive properties of ECTFE coatings during water penetration stage was investigated through characterization tests of the coating micromorphology, phase structure, hydrophilicity/hydrophobicity, microhardness and electrochemical corrosion performance. Additionally, simulation analysis of the coating internal structure and water molecular infiltration law by molecular dynamics was conducted. The results indicate that the addition of CNT can augment the efficacy of ECTFE coating against water penetration, thereby improving the corrosion protection performance. This is primarily attributed to the ability of CNT to reinforce structural stability by impeding the free movement of ECTFE molecular segments and obstructing water molecules from infiltrating. Meanwhile, the hydroxyl groups on the surface of CNT can capture a large number of water clusters through hydrogen bonding and restrict the infiltration of water molecules by occupying osmotic channels. In addition, CNT can prolong the penetration path of water through the labyrinth effect.

Sensitive and rapid detection of bacterial endotoxin with a functional carbon nanotube field-effect transistor biosensor

Endotoxin in the blood can cause unexplained fever, and even death due to endotoxemia and bacteremia. Rapid and sensitive detection of endotoxin has become a priority event to intervene in the occurrence of dangerous diseases in time. In this context, a carbon nanotubes-based field-effect transistor (CNTs FET) nanosensor is developed to realize the rapid, label-free and sensitive detection of endotoxin. The CNTs FET was fabricated by assembling the polymer-sorted high-purity semiconductor CNT films onto the sensing channel. In order to improve the detection sensitivity, carboxylated graphene quantum dots (cGQDs) were coupled to the CNT surface via the poly-l-lysine (PLL). After that, polymyxin B (PMB), which is highly specific for endotoxin, was covalently combined with cGQDs, thus enabling the capture and detection of endotoxin. The method not only displayed an extremely low level of limitation of detection in PBS (4.6 fg/mL) and serum (30.3 fg/mL), respectively, with superior resistance to interference, but also enabled the analysis of Gram-negative bacterial infections in blood samples in a short duration of time. Meanwhile, the receiver operating characteristic curve (ROC) proved the superior diagnostic accuracy of this method (AUC = 0.990). Considering its excellent performance, the constructed CNTs FET biosensor is a promising tool to provide early warning of disease for clinical Gram-negative bacteremia and endotoxemia.

Study of folate-based carbon nanotube drug delivery systems targeted to folate receptor α by molecular dynamic simulations

We designed targeted drug delivery systems containing folate (FOL), the functionalized carbon nanotube (f-CNT) and doxorubicin (DOX), and studied the targeting properties of folate, f-CNT-FOL and DOX/f-CNT-FOL to folate receptor α (FRα). Folate was actively targeted to FRα in molecular dynamics simulations, and the dynamic process, effect of folate receptor evolution, and characteristics were analyzed. On this basis, the f-CNT-FOL and DOX/f-CNT-FOL nano-drug-carrier systems were designed, and the drug delivery process targeted to FRα was studied by 4 times MD simulations. The system evolution and detailed interactions of f-CNT-FOL and DOX/f-CNT-FOL with FRα residues were examined. We found that though the connection of CNT with the FOL could decrease the insertion depth of the pterin of FOL into the pocket of FRα, the loading of drug molecules could reduce this effect. Representative snapshots from the MD simulations were analyzed, showing that the location of DOX on the surface of CNT was constantly changed during the MD simulation, but the surface of the four rings of DOX were almost always parallel to the surface of CNT. The RMSD and RMSF were used to further analyze. The results may provide new insights for the design of novel targeted nano-drug-delivery systems.

Functionalization of Carbon Nanotubes Surface by Aryl Groups: A Review.

The review is devoted to the methods of introducing aryl functional groups to the CNT surface. Arylated nanotubes are characterized by extended solubility, and are widely used in photoelectronics, semiconductor technology, and bioelectrocatalysis. The main emphasis is on arylation methods according to the radical mechanism, such as the Gomberg-Bachmann and Billups reactions, and the decomposition of peroxides. At the same time, less common approaches are also considered. For each of the described reactions, a mechanism is presented in the context of the effect on the properties of functionalized nanotubes and their application. As a result, this will allow us to choose the optimal modification method for specific practical tasks.