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Recently, substantial focus has made in the development of cost effective Pt-free dye sensitized solar cells (DSSCs). In this article we report a potential, Pt-free, carbon based nanocomposite as counter electrode catalyst for dye sensitized solar cells. Graphene oxide (GO) was made into reduced graphene oxide (SSrGO) by irradiating with light (Xe source). Suspension of SSrGO in DMF was spray coated onto fluorine doped tin oxide (FTO) coated glass substrate, followed by spray coat of single walled carbon nanohorns (SWCNH) suspension in DMF. SSrGO and SWCNH coated FTO glass substrate was investigated as an effective Pt-free composite counter electrode (CE) for DSSC and also showed the comparable catalytic activity with Pt. The test cell reveals power conversion efficiency (PCE) of 8.27%, whereas the DSSC module exhibited a PCE of 5.18%. By using the fabricated DSSC module, an electric motor (15 mW) was operated both in indoor and outdoor light conditions. The procedures followed in this work pave a way for the easy fabrication of composite CE towards transparent DSSC modules and further the integration of the DSSC module with the standard Si solar cell is of great potential for various real-time application.

The low density of porous carbon nanomaterials for supercapacitor electrodes has limited their widespread application, despite their ultra-high gravimetric capacitance. In this work, we successfully prepared highly densified composite electrodes of graphene and single-walled carbon nanohorns (SWCNHs) using a simple spray-drying method that is suitable for mass production. To prepare the high-density composite electrodes, water-based mixtures of oxidized SWCNHs (NHOs) and graphene oxides (GOs) were spray-dried in heated air; after spray-drying, GOs dispersed in water were agglomerated in spherical clusters containing NHO nanoparticles. The reduced spray-dried GO/NHO (rS-GO/NHO) composite electrodes exhibited an extremely high bulk density of 1.23 g·cm−3, which is almost double that of commercial activated carbon (AC) and reduced NHO (r-NHO) electrodes, and three times higher than that of rS-GO electrodes. Of the materials tested, the rS-GO/NHO composite electrode had the highest volumetric capacitance (80 F·cm−3 at 1 mA·cm−2) and a low sheet resistance (0.005 Ω· sq.−1), which are far superior to those of commercial AC (57 F·cm−3 at 1 mA·cm−2 and 0.293 Ω·sq.−1, respectively), without the need for a conductive material, such as carbon black. We expect that these high-density graphene/SWCNH composite electrodes with high volumetric capacitances can be substituted for commercial AC materials in energy storage devices, such as supercapacitors.

A glassy carbon electrode (GCE) modified with single-walled carbon nanohorns (SWCNH) and zein (ZE), a prolamin type-protein find in maize, for the differential pulse adsorptive cathodic stripping voltammetric determination of fenitrothion (FT) is proposed. The proposed film was characterized by scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. Regarding the electrochemical characterization, comparing the results obtained by cyclic voltammetry and electrochemical impedance spectroscopy, the modified electrode (SWCNH-ZE/GCE) showed an electroactive surface area 3 times higher and faster electron transfer kinetic than bare GCE. By using differential pulse adsorptive cathodic stripping voltammetry and SWCNH-ZE/GCE the analytical curve exhibited a linear response ranging of 9.9 × 10−7 to 1.2 × 10−5 mol L−1, with a limit of detection of 1.2 × 10−8 mol L−1. The proposed sensor was successfully applied for the determination of FT pesticide in natural water and orange juice samples. Moreover, the electrochemical sensor showed good repeatability and reproducibility arising from the excellent film stability, suggesting that the proposed architecture has broad potential for applications in sensing and biosensing.

γ-valerolactone (GVL) is a fine chemical which is widely used as a green solvent, a fuel additive and a green fuel. It can be produced from lignocellulosic biomass and its derivatives, such as methyl levulinate (ML) via catalytic hydrogenation reaction. In this work, novel hybrid materials of Ni nanoparticles and single-walled carbon nanohorns (Ni/CNHs) synthesized from gas-injected arc-in-water (GI-AIW) method was used as catalysts for producing GVL from ML. Effect of surface modification, oxidation and reduction of Ni/CNHs on their catalytic activity was investigated. For comparison of catalytic activities, Ni on other carbon supports prepared by the conventional wet impregnation and unsupported Ni catalysts were examined. X-ray diffractometry (XRD), transmission electron microscopy (TEM), field-emission scanning electron microscopy (FE-SEM), N2 sorption, thermogravimetric analysis (TGA), Hydrogen-temperature-programmed reduction (H2-TPR), and Fourier Transform Infrared (FT-IR) spectroscopy were employed for elucidating different characteristics of all examined catalysts. It was found that reduced oxidized Ni/CNHs exhibited the highest catalytic performance with 96% conversion of ML, 90% yield, and 93% selectivity of GVL.

In this study, a dual-type responsive electrochemical biosensor was developed for the quantitative detection of α2,6-sialylated glycans (α2,6-sial-Gs), a potential biomarker of tumors. The gold nanorods (AuNRs), which exhibited great specific surface area, as well as good biocompatibility, was synthesized by the way of seed growth method. Furthermore, a biotin-streptavidin (biotin-SA) system was introduced to improve the immunoreaction efficiency. Accordingly, a label-free biosensor was fabricated based on AuNRs-SA for the quick detection of α2,6-sial-Gs by recording the signal of differential pulse voltammetry (DPV). Furthermore, to expand the ultrasensitive detection of α2,6-sial-Gs, a carboxylated single-walled carbon nanohorns/sulfur-doped platinum nanocluster (c-SWCNHs/S-PtNC) was synthesized for the first time as a novel signal label, which showed an excellent catalytic performance. The usage of c-SWCNHs/S-PtNC could significantly amplify the electrochemical signal recorded by the amperometric i-t curve. Herein, a sandwich type biosensor was constructed by combining the AuNRs-SA on the electrode and c-SWCNHs/S-PtNC (signal amplifier). The label-free biosensor possessed a linear range from 5 ng mL−1 to 5 μg mL−1 with a detection limit of 0.50 ng mL−1, and the sandwich-type biosensor possessed a wide linear range from 1 fg mL−1 to 100 ng mL−1 with a detection limit of 0.69 fg mL−1. Furthermore, the biosensor exhibited excellent recovery and stability, indicating its potential for use in actual samples.

Among various carbon materials, nitrogen doped single walled carbon nanohorns (N-SWCNHs) have a unique structure of clustered conical cages (2–5 nm in diameter and 40–50 nm in length) arranged in dahlia, bud and seed-like configurations. Each conical cage has five pentagons at their tips which act as potential reactive site with their own distinct chemistry. We exploited these reactive sites of N-SWCNHs by preferentially growing germanium nanocrystals (Ge NCs) onto their conical tips using oleylamine as a mild reducing agent. Therefore, Ge decorated N-SWCNHs (Ge@N-SWCNHs) composite was used, for the first time, as active anode material for lithium ion batteries providing high and stable capacity of 1285 mAh/g at 0.1C after 100 cycles. Our results show that preferential growth of Ge Nanocrystals (NCs) on the tips of N-SWCNHs not only allows high utilization of active material but prevents the aggregation of Ge NCs after multiple cycling. Finally, we highlight the potential role of N-SWCNHs as cheap and industrially scalable conductive host for next generation lithium ion batteries.

Single-walled carbon nanohorns (SWCNHs) was utilized as an ion-to-electron transducer to fabricate all-solid-state ion-selective electrodes (ISE) for the first time. To evaluate the performance of developed SWCNHs-based calcium ISE, various electrochemical experiments were carried out. A Nernstian response (29.69 ± 0.24 mV/decade, R2 = 0.9996) was acquired across a broad linear range between 10−6 and 10−2 M, and the detection limit of 10−6.1 M was achieved in the meantime. Additionally, water layer test and reversed chronopotentiometry were used to estimate the long-term and short-term stability of SWCNHs-based ISE, respectively, indicating SWCNHs is capable of enhancing potential stability on account of its hydrophobicity. Furthermore, a SWCNHs-based reference electrode (RE) was fabricated by directly coating a photo-polymerised reference membrane (RM) onto a SWCNHs modified electrode. Results demonstrated that the SWCNHs-based RE exhibited slight potential fluctuation for common ions with different charges over a wide concentration range of calibration. Based on these superior results, an integrated all-solid-state SWCNHs-based potentiometric sensing device combined SWCNHs-based ISE and SWCNHs-based RE was constructed for detecting calcium, which shows a Nernstian response with a slope of 27.14 mV/decade. This developed electrode in the aid of SWCNHs exhibits fast response as well as outstanding potential stability, making it extreme promising for routine sensing application.

In this study, we report an electrochemical study based on nanocellulose (NC) and single-walled carbon nanohorns (SWCNH). SWCNH and NC ensure large surface area, good conductivity, high porosity and chemical stability, becoming attractive for electrodes. The materials were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), Scanning Electron Micrograph (SEM), Transmission electron microscopy (TEM), dynamic light scattering (DLS) and zeta potential. Using XRD and FTIR it was possible to observe particular characteristics of NC and SWCNH. The presence of dahlia-like assemblies on the NC surface was observed by MEV and TEM. Then, we investigated the electrochemical behavior of NC-SWCNH, which showed the excellent results when it was used guanine and adenine, as proof of concept, by using cyclic and linear sweep voltammetry (LSV). LSV was also employed for simultaneous detection resulting in limits of detection of 1.7 × 10−7 mol L−1 and 1.4 × 10−6 mol L−1, for guanine and adenine, respectively. In addition, the proposed electrode was applied for determination of both bases in synthetic human serum and fish sperm. We demonstrate that it is possible to use NC, a renewable material, in conducting thin films with SWCNH, and due to simplicity in the preparation and high conductivity, this new thin film could be extended for others electrochemical purposes such as sensing and biosensing.

Application of carbon nanomaterials to near-infrared light-mediated phototherapy has attracted great interest. However, their practical use in biological systems is severely limited by their poor water dispersibility, inevitable adsorption of plasma proteins, and their single therapeutic function. Herein, we prepared a phycocyanin (PC)-functionalized single-walled carbon nanohorns (PC@SWNHs) hybrid, where PC is used to preform a protein corona around the SWNHs through non-covalent interface interactions. In the PC@SWNHs, the preformed PC corona effectively improves the water dispersibility of the SWNHs and protects them from plasma protein adsorption. In addition, the excellent photodynamic activity of PC overcomes the inability of SWNHs to generate reactive oxygen species. The SWNHs not only give the hybrid a photothermal therapy (PTT) function, but they also enhance the photostability of PC. These characteristics of the PC@SWNHs are confirmed by in vitro and in vivo experiments, where synergistic photodynamic therapy (PDT)/PTT growth inhibition of tumors is achieved. The PC@SWNHs also act as a photoacoustic/thermal imaging agent to visualize the in vivo treatment process. Hence, this work not only paves the way to use the complementarity between SWNHs and proteins for multifunctional cancer theranostics, but it also allows for a better understanding of bio–nano interface interactions between them.

We firstly reveal the unique tendency in the capacitance of an electric double layer capacitor (EDLC) made of single-walled carbon nanohorns (SWCNHs), where there is an optimized value of specific surface area (SSA) to achieve the high capacitance value at a high charge-discharge rate. As a result, in the experimental observation, SWCNHs treated by oxidation in air at 550 °C can exhibit 963.4 m2/g of SSA and 286.6 F/g of EDLC capacitance, whereas the ones treated at 500 °C can exhibit 797.5 m2/g and 316.4 F/g at a high scan rate of 100 mV/s, although the SSA-capacitance relation seems ordinal at 5 mV/s. This result is against a common sense that the higher the SSA, the higher the EDLC capacitance. This unique relationship between the SSA of SWCNHs and the capacitance can be explained by consideration of the hierarchical pore structures of SWCNHs, including the internal mesopore zone and inner-core micropore zone, and the diffusion limitation of ionic species in these different structures. These pores are interlinked via the nanowindows opened by the oxidation treatment, and the nanowindow-link can be enhanced by temperature elevation from 500 to 550 °C, while the superficial mesopore can be partially destroyed at 550 °C.

Single-walled carbon nanohorns (SWNHs) have been shown to be effective photothermal enhancers and drug delivery agents for potential cancer therapy, particularly for the eradication of bladder cancer lesions. In this study, the potential for SWNHs to serve as nanotheranostic vehicles is demonstrated through simultaneous delivery of the chemotherapeutic cisplatin from SWNH cone interiors and imaging of the nanoparticle transport to tumor cells using conjugated quantum dots (QDs). Following the formation of cisplatin-modified SWNH-QD (SWNH-QD + cis) hybrids, their characterization by scanning and transmission electron microscopy (STEM, TEM), energy dispersive spectroscopy (EDS), and dynamic light scattering (DLS) were performed to characterize the composite nanoparticles. Drug release profiles and 50% inhibitory concentration (IC50) determination showed that QDs do not hinder the therapeutic ability of SWNHs. In addition, the hybrids were trackable over the course of a 3 day period, which indicates that internalized SWNHs can continue to deliver therapy after removal of the nano-agents from the cell culture. This unique SWNH hybrid can successfully be used as an imaging agent to study nanoparticle transport and consequently the delivery of a therapeutic to the targeted cancer cells.

Fibrous aggregates of single-walled carbon nanohorns (carbon nanobrushes: CNBs) were prepared by CO2 laser ablation of an iron-containing carbon target with rotations under nitrogen atmosphere and ambient pressure. The rotation speed of the target and concentration of iron contained in it were controlled so as to increase the yield of CNBs. As a result, many CNBs were obtained at a rotation speed of 1 rpm and iron concentration above 1 at. %, although the samples still contained spherical single-walled carbon nanohorn aggregates (CNHs). The sheet resistivity of the samples containing both CNBs and CNHs decreased with the CNB content, which indicates that the CNBs formed a good conducting path. By forming supercapacitor electrodes, the capacitances of mixture of CNBs and CNHs, CNHs, and activated carbon were similar, i.e., 20, 21, and 23 F/g, respectively, at 0.1 A/g. However, the capacitance of the mixture of CNBs and CNHs at a discharge current of 5 A/g was about 1.4 and 6 times higher than that of the CNHs and activated carbon. These newly discovered CNBs should definitely increase the advantages of nanocarbon in various fields, especially in electronic devices.

A novel amplified electrochemiluminescence (ECL) immunoassay based on single-walled carbon nanohorns (SWCNHs) labels and enzymatic biocatalytic precipitation (BCP) was proposed for the detection of neuron-specific enolase (NSE) for the first time. In this system, the dimercaptosuccinic acid stabilized CdTe (DMSA-CdTe) quantum dots (QDs) as ECL emitter showed excellent ECL behavior and then employed as the NSE antibody (Ab1) immobilization film for the subsequent sandwich-type Ab1-Ag affinity interactions. Improved sensitivity was achieved through using the SWCNHs effectively to expand the amount of secondary antibody (Ab2) and horseradish peroxidase (HRP) loading. In addition to the much enhanced steric hindrance, compared with the single HRP-Ab2, the presence of plentiful HRP would further stimulate the BCP onto the electrode surface for signal amplification, concomitant to the BCP products absorption that lowered ECL intensity. As a result of the multisignal amplification in this ECL immunosensor, it possessed excellent analytical performance. The target NSE could be detected from 1 × 10−9 g L−1 to 1 × 10−3 g L−1 with a detection limit of 4.4 × 10−10 g L−1.

Poly(amic-acid) modified single-walled carbon nanohorns (PAA/SWCNH-COOH) contained dual-functional groups (amide and carboxyl) were synthesized by in-situ polymerization and used for the elimination of uranium (VI). It was found that the adsorption capacity of SWCNH-COOH increased significantly after grafting PAA chains, and the theoretical monolayer adsorption capacity of PAA/SWCNH-COOH could reach 216.0 mg/g. The adsorption capacity of this material could remain up to 90% of the initial value after 5 times of reuse. Moreover, PAA/SWCNH-COOH has an excellent adsorption selectivity, which could be attributed to the synergistic adsorption effects between amide and carboxyl groups. To further study the interaction mechanism between uranium ions and the adsorbents, the quantum chemical calculations were performed using DFT method. The simulation results show that both amide and carboxyl groups have a strong interaction with uranium ions, which ensures the high adsorption capacity of this material. This research proved that the PAA/SWCNH-COOH is a promising adsorption material for removing uranium from wastewater and it also sheds a light on the interaction mechanism between bifunctional adsorbents and uranium ions.

Ultrasonic-assisted liquid-phase exfoliation is one of high-efficiency strategies for preparing two-dimensional (2D) materials. Herein, we report a facile and green synthesis of the phosphorene (BP) obtained from bulk black phosphorus crystal in the ionic liquid (IL) 1-ethyl-3-methylimidazoliumtetrafluoroborate ([EMIm]BF4) through ultrasonic-assisted liquid-phase exfoliation under the continuous nitrogen atmosphere. To gain more insight, the morphology and composition of the as-prepared BP were characterized. The prepared BP showed satisfactory stability in ambient condition containing oxygen and water. In the following, single walled carbon nanohorn (SWCNH) was selected to enhance electrocatalytic capacity and endow oxidase-like (nanozyme) characteristics, which was further applied for electrochemical sensing of 5-hydroxytryptamine (5-HT). Derivative techniques were employed for treating voltammograms to obtain sharper and narrower voltammetric peak, transform asymmetric peak into much more symmetrical peak, reduce background interference, eliminate personal error and directly read the accurate value. Machine learning (ML) model based on artificial neural network (ANN) algorithm as an artificial intelligence approach is adopted to establish smart sensing system via the relationship between concentrations and currents in comparison with traditional linear regression model. The BP-IL-SWCNH nanozyme sensor displayed excellent electrocatalytic ability for second-order derivative voltammetric smart analysis of 5-HT range from 0.3 to 115 µM under optimal conditions.

A novel CdTe quantum dots - single walled carbon nanohorns (CdTe-SWCNHs) nanocomposite was synthesized via a one-pot method for photoelectrochemical (PEC) aptasensing detection of streptomycin (STR). The CdTe-SWCNHs nanocomposite shows 3.2-times amplified PEC activity in comparison with CdTe quantum dots (QDs). By using aptamers as recognition element and CdTe-SWCNHs as photoactive species, a PEC aptasensor was fabricated for the high sensitive and selective detection of STR. Under the optimized conditions, the as-fabricated PEC aptamer sensor exhibits a linear response ranging from 0.1 nM (0.15 μg kg −1 ) to 50 nM (72.85 μg kg −1 ) with a detection limit ( S / N = 3) of 0.033 nM (0.05 μg kg −1 ). The aptasensor has successfully applied for the determination of streptomycin in honey sample, which provides a new method for detection of streptomycin.

Ochratoxin A (OTA), is one of the most commonly found mycotoxins in food. It is primarily produced by Aspergillus ochraceus and Penicillium verrucosum. OTA can causes serious damages to liver and kidney, increases the teratogenicity, and has been considered as a potential carcinogen (group 2 B). In this study, we demonstrated a new detection system for the detection of OTA using fluorescence biosensing according to an anti-OTA aptamer and fluorescence quencher using single-walled carbon nanohorns (SWCNHs). In the presence of OTA, the OTA-specific aptamer underwent the conformation change from a random coil to an antiparallel G-quadruplex. The latter one was resistant to being adsorbed onto SWCNHs, leading to the pertection of the fluorescence of SYBR Gold. As a result, the remained fluorescent intensities correlated with the concentrations of OTA. The detection limit of OTA was 2.3 ng/ml, meanwhile the linear detection range was 5–500 ng/ml, with a satisfactory linear correlation (R2 = 0.992) of the fluorescence intensity and the logarithm of OTA concentrations. The aptasensor was subjected to quantify the concentration of OTA in red wine samples. As a result, this label-free aptasensor was suitable for the test of OTA in food samples.

The high surface area and electrical conductivity of few-layered graphene would make it an ideal catalyst support and electrode in fuel cells apart from its susceptibility to oxidative corrosion. Here we report the single-step, bottom-up synthesis of oxidation-resistant boron-doped graphene and show its increased stability in the aggressive electrochemical environment of intermediate temperature solid acid fuel cells (SAFCs). Boron was shown to alter the growth mode of single walled carbon nanohorns by laser vaporization to produce high yields of thin ( 140 °C, with large fractions of multilayered B-GLFs surviving 10 °C/min ramps to 1000 °C. These B-GLFs provided a stable Pt catalyst support and electrode over 40 h operation in SAFCs with cesium dihydrogen phosphate electrolyte operating at 250 °C, as opposed to undoped GLFs or SWCNHs which were nearly completely consumed. The facile synthesis and oxidation-resistant properties of boron-doped GLF appear promising for graphene applications in oxidizing environments.

The importance of sensing hydrogen peroxide (H2O2) is due to its ubiquity, being extensively used in industry and also being a biologically relevant side-product of several enzymatic processes. Electrochemical sensing is one of the most robust and simple methods for sensing H2O2 and the discovery of new electroactive materials, particularly at the nanoscale, represents a very hot topic of research. Here, we prove that upon appropriate integration of oxidized single-walled carbon nanohorns (ox-SWCNHs) into a per se moderate H2O2 sensor such as cerium dioxide (CeO2), the sensitivity toward H2O2 is enhanced by almost two orders of magnitude (from 0.4 to 160 μA cm−2 mM−1), on par with that of state-of-the-art metal or metal oxide-based sensors. The modified electrode is also very stable (82% response after 2 weeks of continuous use) and the results highly reproducible. The developed nanohybrid ox-SWCNHs@CeO2, characterized fully and whose average size is about 70 nm as measured by both TEM and AFM, was also tested in real case studies such as washing liquids and milk and was confirmed to be a robust and highly selective material, being not affected neither by the presence of complex matrices, nor by interferents in several organic substrates. The high recovery confirmed the excellent specificity and flexibility of this new electrocatalytic material. Fil: Bracamonte, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. University of Trieste; Italia Fil: Melchionna, Michele. University of Trieste; Italia Fil: Giuliani, Angela. University of Trieste; Italia Fil: Nasi, Lucía. CNR-IMEM Institute; Italia Fil: Tavagnacco, Claudio. University of Trieste; Italia Fil: Prato, Maurizio. University of Trieste; Italia. Carbon Nanobiotechnology Laboratory; España. BasqueFdnSci; España Fil: Fornasiero, Paolo. University of Trieste; Italia

Boron- and nitrogen-codoped single walled carbon nanohorns (BN-SWCNHs) were prepared by CO 2 laser ablation of a boron-containing carbon target under nitrogen atmosphere. The structures were spherical SWCNH aggregates containing many graphite-like thin sheets (GLSs), which was different from general SWCNHs. X-ray photoelectron spectra indicated that the doped quantities of boron and nitrogen were about 1.2 and 1.0 at.%, respectively. The boron and nitrogen atoms were implanted partially as the BN bonding in a graphene lattice, although they were also implanted individually as three-fold coordinated sp 2 bonding. The boron-doped GLSs were preferentially prepared by CO 2 laser ablation of a boron-containing carbon target under argon atmospheres. As a result, we found that the boron accelerated the formation of GLSs. The simple CO 2 laser ablation method will be useful for heteroatoms doping into carbon nanohorns.

A novel phosphomolybdic acid/single-walled carbon nanohorn based amperometric sensing platform was successfully constructed for determination of glucose. Single-walled carbon nanohorn acted as an active matrix and was used to immobilize phosphomolybdic acid. As-prepared phosphomolybdic acid/single-walled carbon nanohorn composite was characterized by SEM, EDX and XRD. Electrochemical behaviors of modified electrodes were characterized by cyclic voltammetry and chronoamperometry. Electrochemical investigations of phosphomolybdic acid/single-walled carbon nanohorn electrode showed three well-defined pairs of redox peaks and rapid electron transfer between electrode and electrolyte. Excellent electrocatalytic performance was obtained due to the synergistic effect of phosphomolybdic acid and single-walled carbon nanohorn. It was concluded that the linear amperometric response to glucose was achieved in the concentration range of 0.035 mM to 4.0 mM, and the detection limit was calculated as 2.4 μM. Moreover, as-prepared phosphomolybdic acid/single-walled carbon nanohorn electrode exhibited prominent selectivity, stability and reproducibility, making it a promising tool for sensitive non-enzymatic determination of glucose.

To store more energy in limited spaces, the volumetric performance of energy storage devices used in electric vehicles and portable electronics has attracted more research attention than their gravimetric performance. Herein, we describe the preparation of N/O co-doped single-walled carbon nanohorns (SWCNH) using chemical vapor deposition with pyridine followed by acid treatment to obtain a supercapacitor electrode material with high specific volumetric capacitance. The synthesized N/O co-doped SWCNH (N and O contents of 6.1 and 9.1 at%, respectively) electrode had a higher bulk density (1.05 g cm−3) than that of the pristine SWCNH electrode (0.86 g cm−3). Moreover, the N/O co-doped SWCNH supercapacitor electrode exhibited drastically increased specific volumetric, gravimetric, and areal capacitances (123 F cm−3, 117 F g−1, and 91.4 μF cm−2, respectively) in 1 M H2SO4 electrolyte, compared with those of a pristine SWCNH electrode (36 F cm−3, 42 F g−1, and 11.4 μF cm−2, respectively). The superior electrochemical performances are associated with enhanced pseudocapacitive contribution and high bulk density of electrode upon N/O co-doping. The simple method described herein for producing SWCNH electrodes with high bulk density and high specific volumetric capacitance should contribute to the development of supercapacitors with high volumetric performance.

Single-walled carbon nanohorns (SWCNHs), a type of tapered carbon nanomaterials, are generally prepared by laser ablation method, arc method, and Joule heating method without the addition of metal catalysts, which makes them pure and environmentally friendly. The obtained aggregates of SWCNHs mainly have three different types of structure, dahlia-like, bud-like, and seed-like. Over the past few decades, they have been widely used in the fields of energy, medicine, chemistry, and sensing. The SWCNHs-based sensors have shown high sensitivity, rapid response, and excellent stability, which are mainly attributed to the excellent electrical conductivity, large electrochemical window, large specific surface area, and mechanical strength of SWCNHs. In this review, we systematically summarizes the structures, synthesis methods, and sensing applications of SWCNHs, including electrochemical sensors, photoelectrochemical sensors, electrochemiluminescence sensors, fluorescent sensors, and resistive sensors. Moreover, the development prospects of SWCNHs in this field are also discussed.

Catalyst-free, high-yield (kilogram-scale) and high-purity (>95%) synthesis of dahlia flower and “bud-like” single-walled carbon nanohorns (SWCNHs) has been achieved via DC arc discharge under high pressures of Ar gas up to 0.35 MPa. In contrast, the mean size (100 nm) of SWCNH particle was twice as large as the counterpart in the literature via arc discharge. A new growth mechanism is proposed rationally to explain the mass production of SWCNHs under positive pressures, the growth mechanisms of SWCNHs rely mainly on the concentration of carbon clusters, rather than the temperature gradient of arc zone.

In this study, Titania (TiO 2 ) based composites reinforced with 2 wt% of various carbon nanomaterials were prepared using spark plasma sintering (SPS). Prior to SPS, the samples were ball milled. The reinforcements used in the composites were graphene nanoplatelets (GNP), carbon nanotubes (CNT) and single walled carbon nanohorns (SWNH). The ball milled powders and SPS compacts were characterized using various techniques. Mechanical and photocatalytic properties of the SPS composites were evaluated and compared for different nano-carbon reinforced TiO 2 composites. X-ray diffraction and Raman spectroscopy studies confirmed that the milled powders comprised of Anatase phase which transformed into Rutile phase during SPS. Nano transformation twins were observed in Rutile grains. Fractured surfaces showed that the reinforcements were well bonded with the TiO 2 grains and the SWNH reinforcement resulted in comparatively finer grain size. Nanoindentation studies showed that the hardness and elastic modulus of GNP reinforced composites was 78% and 30% respectively higher compared to TiO 2 matrix. The hardness and modulus of the CNT reinforced TiO 2 increased by 22% and 5.4% respectively while that of the SWNH reinforced TiO 2 increased by 11% and 23% respectively. GNP and CNT reinforced TiO 2 exhibited superior photocatalytic activity for the degradation of methylene blue dye compared to pure TiO 2 .

A dual-signalling electrochemical approach has been developed towards aconitine based on competitive host-guest interaction by selecting methylene blue (MB) and p-sulfonated calix[8]arene functionalized single-walled carbon nanohorns (SCX8-SWCNHs) as the "reporter pair". Upon the presence of aconitine to the performed SCX8-SWCNHs·MB complex, the MB molecules are displaced by aconitine. This results in a decreased oxidation peak current of MB and the appearance of an oxidation peak of aconitine, and the changes of these signals correlate linearly with the concentration of aconitine. A linear response range of 1.00-10.00μM for aconitine with a low detection limit of 0.18μM (S/N=3) was obtained by using the proposed method. This method could be successfully utilized to detect aconitine in serum samples. This dual-signalling sensor can provide more sensitive target recognition and will have important applications in the sensitive and selective electrochemical detection of aconitine.

The effect of different surfactants on the removal efficiency of wiping surfaces contaminated with single walled carbon nanohorns (SWCNHs) was studied. To this end, sodium dodecylbenzenesulfonate (SDBS) and sodium dodecyl sulfate (SDS) surfactants were used, and their removal efficiencies with water only and with cleaning with a dry wipe were compared. The surfactant concentrations and wipe pressure during the wiping process were varied, and significant effects on removal efficiency were found. In addition, the results were compared with those obtained with single-walled carbon nanotubes (SWCNTs) and multi-walled CNTs (MWCNTs) and the differences among these nanostructures were reported. The results suggest that SDS and SDBS are good candidates for removal of SWCNHs deposited on silicon wafers with SDS removal efficiencies capable of exceeding 90%. In addition, the results show that there is an optimum wiping pressure and surfactant concentration with the highest removal efficiency. A direct relationship was also found between wipe saturation and removal efficiency of SWCNHs deposited on silicon substrates. The differences between individual nano structures were perceptible in spite of following similar broad trends; for instance, SWCNH contaminated surfaces in general proved more difficult to clean than surfaces contaminated with the other nanostructures.

Adsorption of polyethylene glycol conjugated phospholipids with various PEG chain length (DSPE-PEG5000, 2000, 750) onto single-walled carbon nanohorns (SWCNH), a type of graphene nano-tubule, in aqueous solution was investigated by means of high-resolution magic angle spinning (HRMAS) 1H NMR. Peak integral ratio of PEG chains and alkyl chains of DSPE-PEGs in the NMR spectra linearly decreased to zero with the increase of SWCNH quantity, indicating that the adsorption of DSPE-PEGs on SWCNH was virtually irreversible. The area of SWCNH surface allocated to the individual DSPE-PEG5000, 2000, 750 molecule were estimated to be 7.06, 5.18, and 4.45 nm2, respectively. Coverages of the alkyl chains on the surface area of SWCNH were about 28%, 39% for DSPE-PEG5000, 2000 and 46% for DSPE-PEG750, suggesting single layer adsorption. We presumed that the electrostatic repulsion may prevent DSPE-PEGs from multiple layer and keep away neighbouring DSPE-PEGs on the surface. According to the molecular areas of the DSPE-PEGs, PEG5000 and 2000 chains were considered to be in brush-regimes, while PEG750 was considered to be in mushroom regime on the SWCNH surface.

A novel electrochemical sensor was developed by electrodepositing gold nanoparticles on the single-walled carbon nanohorns modified glassy carbon electrode. We used the prepared sensor to determine hydrazine for the first time. The results show that the modified electrode has good electrocatalytic activity toward the oxidation of hydrazine. Under the optimized conditions, two wide linear segments were observed between the catalytic currents and the concentration of hydrazine within the range of 0.005–3.345 mM with a detection limit of 1.1 μM (s/n = 3). The diffusion coefficient of hydrazine was also estimated using chronoamperometry. Additionally, the sensor showed excellent sensitivity, selectivity, and reproducibility properties.

Hybrid electrocatalysts made from ultrafine Pd nanoparticles strongly coupled on single-wall carbon nanohorns (Pd/CNH) are prepared via a facile and scalable approach. Benefiting from the unique interconnected open-pore microstructure of CNHs as well as the numerous exposed Pd active sites, such an architectural design can substantially increase the Pd utilization efficiency and thereby reduce the overall dosage of metal Pd. Strikingly, the newly-developed Pd/CNH hybrid with an ultra-low Pd loading amount of 5.0 wt% exhibits high forward anodic peak current densities of up to 1420.4 and 1910.6 mA mg−1 toward formic acid and methanol oxidation, respectively, both of which are significantly superior to those of commercial 20.0 wt% Pd/carbon black catalyst. This study may offer an economic option and a new vision for the development of the next-generation low-cost fuel cell anode catalysts.

An electrochemical biosensor was proposed utilizing an improved amplification strategy for the rapid detection of sulfamethazine (as a model target) in aquatic environments. In this competitive immunoassay, cetyltrimethylammonium bromide-capped gold nanoparticles (CTAB-AuNPs) were used as a signal amplifier and electrode matrix and coated with an antigen-antibody (Cag-Ab1) specific binding system as a recognition unit for the target compound. In addition, silver nanoparticle labels were functionalized with dendritic fibrous nanosilica (DFNS@AgNPs) and decorated onto chitosan/single walled carbon nanohorn (CS/SWCNH)-modified glass carbon electrodes (GCEs), which improved the electron transfer rate and increased the surface area, enabling more coating antigens to be captured. Under acidic conditions, massive amounts of the Ag+ bound to the surface of the AuNPs dissolved, and consequently, formed Ag+@CTAB-AuNP complexes, which resulted in a distinctly improved peroxidase-like activity and enhanced current response. Furthermore, the destroyed Ab1-Ab2-DFNS conjugation greatly decreased the impedance, bringing about the amplification of the electrochemical signals. After optimization of the parameters, the proposed approach exhibited excellent performance, including good sensitivity (LOD, 0.0655 ng/mL) and satisfactory accuracy (recoveries, 79.02%–118.39%; CV, 3.18%–9.82%), which indicates the great potential of this strategy for the rapid detection of trace pollutants in the environments.

Carbon nanohorns (CNHs) hybridized with Fe nanoparticles (Fe-CNHs) were synthesized by a gas-injected arc-in-water (GI-AIW) method using a holey graphite anode in which Fe wires were inserted. Because of the ferromagnetic property of the Fe nanoparticles, Fe-CNHs can be manipulated by applying a magnetic field. In this study, a heat treatment on Fe-CNHs under a vacuum condition at 50 Pa up to 800 °C was performed to enhance their magnetic property. An analysis of AC magnetic susceptibility at room temperature indicated that the magnetic susceptibility of Fe-CNHs was enhanced by more than twice using this vacuum heat treatment. This increase in the magnetic susceptibility should enhance the handling performance of the Fe-CNHs in fluid media, and this finding should be useful to develop catalyst supports which can be recovered using magnetic field. Additionally, an X-ray diffraction (XRD) analysis indicated that Fe was oxidized partially by residual air to form ferrimagnetic Fe3O4 (magnetite) in the vacuumed system, contributing to the enhancement in the magnetic susceptibility of Fe-CNHs. Meanwhile, the growth of bcc Fe crystal grain was observed. It was remarkable that the products observed here did not suffer from the transformation of Fe to paramagnetic Fe2O3. Also, there was no serious damage in the carbonaceous part of Fe-CNHs detected by microscopic observation. N2 adsorption analysis suggested that only a moderate increase in BET specific surface area of Fe-CNHs was observed by the vacuum heat treatment. All of these results suggest that while the magnetic property of Fe-CNHs is highly enhanced, most of the carbonaceous structures can be preserved by the present method. Such functionalization of Fe-CNHs cannot be achieved by conventional methods using heat treatment in air or in CO2–N2 mixture.

Cost-effective synthesis of single walled carbon nanotube (SWCNT) and single walled carbon nanohorn (SWCNH) hybrids, in a single step, by electric arc discharge technique in open air, at lower current densities is reported. The rate of production of the hybrids is 3-5 g/h. The presence of SWCNTs and SWCNHs is confirmed by a transmission electron microscope (TEM). In addition to conventional larger Dahlia-like aggregates of nanohorns, unique nearly-spherical shaped and relatively smaller sized aggregates (mean size ? 25 nm) of nanohorns are formed along with thin bundles (mean diameter ? 5.7 nm) of SWCNTs. � 2015 Elsevier B.V. All rights reserved.

The simultaneous esterification of palmitic acid and transesterification of tributyrin is investigated using a solid acid catalyst newly developed. This catalyst consists of porous single-walled carbon nanohorn (SWCNH) dispersed with Fe/Fe2O3-mixed nanoparticles. The esterfication of palmitic acid is initially catalyzed by this catalyst, and the transesterification of tributyrin can be observed after most of palmitic acid was consumed. Contrary to a general expectation that the addition of a free fatty acid usually has poisonous effect on transesterification of tributyrin, the addition of palmitic acid shows an effect to enhance the yield of methyl butyrate. As one of the reasons, the palmitic acid adsorbed on Fe/Fe2O3 particles placed in the pores of the catalyst may attract tributyrin molecules, and tributyrin concentrated thereon may diffuse to the acidic sites on the catalyst. However, this effect seems to be reduced significantly when the reaction temperature is high.

Mixtures of straight and defect-free multiwalled carbon nanotubes (MWCNTs), single walled carbon nanohorns (SWCNHs), and multiwalled carbon nanohorns (MWCNHs) were prepared by the arc discharge method. Functionalized Carbon Nanotubes (FCNTs) composed of MWCNTs, MWCNHS and SWCNHs were obtained using acid functionalization process. TiO2/FCNTs (CTP) nanohybrid photocatalysts were obtained with different amounts of FCNTs (2-20 wt%), by wet impregnation method. The photocatalytic activity of both pristine TiO2 as well as the nanohybrids were studied in aqueous glycerol solution under solar irradiation. Reaction parameters such as amount of catalyst and amount of FCNTs in nanohybrids were optimized to ensure high rates of H2 production. With a relatively low amount of pristine TiO2, a high rate of H2 production of 2134 ?mol h-1 gcat -1 has been obtained and is likely due to several factors such as well dispersed catalyst, reduced particle-particle agglomeration, resulting in enhanced light absorption (less light shielding), improved separation of charge carriers and utilization for red-ox reactions. Even better results were obtained with the use of nanohybrid catalysts. The enhanced photocatalytic activities of the nanohybrid catalysts are ascribed to the synergetic effects of FCNTs that minimize light reflection which promotes enhanced solar light sensitization, good dispersion of the catalysts in the reaction solution, and improved surface-interface reactions of photogenerated charge carriers. In the present study 10 wt% FCNTs in nanohybrid (CTP-10) exhibited superior photocatalytic activity for H2 generation, nearly 3 times higher than that of pristine TiO2 catalyst. The CTP-10 photocatalyst exhibited photostability under the experimental conditions studied. The nanohybrid photocatalysts were characterized in order to confirm the crystal structure, morphology, surface chemical composition and optical properties. The present work demonstrates the unique beneficial photocatalytic properties of carbon nanotubes and nanohorn mixtures in nanohybrid photocatalysts, for enhanced H2 production. � 2014 Hydrogen Energy Publications, LLC.

We prepared lauric acid based phase change nanocomposite embedded with chemically functionalized single-walled carbon nanohorns and measured its thermal properties. We report contrasting enhancements in thermal conductivity of such nanocomposites in the solid and liquid phase for the same loading of nanohorn inclusions. Maximum thermal conductivity enhancement in solid and liquid phase at 2 vol% is found to be ∼37 and ∼11%, respectively. The nanocomposites’ thermal conductivity enhancement is compared with calculations of effective medium theory considering the role of interfacial thermal transport. Model calculations show that Kapitza resistance is an order of magnitude lower at the solid–solid interface compared to the solid–liquid interface. Differential scanning calorimetry study of the nanocomposites shows that the phase change temperature and enthalpy marginally increases to that of pristine material. Such a nanocomposite with enhanced thermal transport and phase change enthalpy makes it a promising candidate for thermal energy storage applications.

Septicemia is a serious disease that requires early diagnosis, and procalcitonin (PCT) serves as a diagnostic biomarker for this disease. Traditional clinical detection (via immune-gold chips) remains difficult and expensive. An electrochemical immunosensor based on new nanomaterials may provide a solving approach. Herein, an ultrasensitive sandwich electrochemical strategy for PCT detection was developed. Firstly, reduced graphene oxide (rGO)–gold (Au) nano-composite film was used as the immunosensor platform to increase the amount of PCT antibody 1(Ab 1 ) immobilized. Next, single-walled carbon nanohorns (SWCNHs)/hollow Pt chains (HPtCs) complex was firstly utilized to label PCT Ab 2 as signal tags. For SWCNHs with few side effects, high surface area and HPtCs with higher specific surface, better catalytic activity, complex synthesized from both may provide more advantages. Moreover, to amplify signal, HPtC catalytic activity with H 2 O 2 was enhanced by horseradish peroxidase (HRP) for dual synergy amplification. The whole results demonstrated that the proposed immunosensor exhibited fast operation, high sensitivity, good reproducibility, acceptable stability and ideal selectivity compared with traditional method. The linear calibration of the immunosensor ranged from 1.00 pg/mL to 2.00×10 1 ng/mL with a detection limit of 0.43 pg/mL. Analytical application results revealed that the immunosensor matched with the real concentrations of serum samples. Overall this immunosensor may provide a new alternative strategy for PCT detection.

The voltammetric behaviors of dihydroxybenzene isomers were studied at the single-walled carbon nanohorn modified glassy carbon (SWCNH-modified GC) electrode. Compared with the bare electrode, SWCNH-modified GC electrode has stronger electrocatalytic activity for the oxidation of dihydroxybenzenes with the increase in peak current and the decrease in peak separation (ΔEp) between the anodic and cathodic peaks. Furthermore, the three isomers can be determined simultaneously and sensitively by using linear sweep voltammetry at the SWCNH-modified GC electrode. For hydroquinone, catechol, and resorcinol, the oxidation peak currents are linear with the concentrations in the range of 0.5–100 μM, 0.5–100 μM, and 1.0–100 μM, respectively. Their detection limits at a signal-to-noise ratio of 3 are 0.1 μM, 0.2 μM, and 0.5 μM, respectively. These results make SWCNH-modified GC electrode a promising candidate for the simultaneous determination of isomers.

A novel micro-solid-phase extraction approach is presented. It consists of a borosilicate disk with oxidized single-walled carbon nanohorns (o-SWNHs) immobilized in its pores. The o-SWNH disk is placed in the screw of a portable drill that allows the extraction unit to be stirred inside the sample. The technique was applied to the extraction of benzophenone-3 from swimming pool water samples, followed by its determination with ultrahigh performance liquid chromatography with photodiode array detection. The variables affecting extraction were optimized, and the method was characterized in terms of linearity, limit of detection (0.16 μg L− 1) and precision (the relative standard deviation is lower than 11.9 %). The enrichment factor is as high as 1379 and it involves an absolute recovery of 68.9 %. Relative recoveries are close to 90%. The method is likely to represent a new approach towards microextraction of organic species using this nanomaterial.

Carbon nanomaterials, such as single-walled carbon nanohorns (SWCNHs) and carbon nanotubes, demonstrate great potential as drug delivery systems. However, no reports to date have detailed the use of SWCNHs as oral drug carriers. This study shows for the first time the actions of orally-administered SWCNHs in normal mice and mice with dextran sulfate sodium (DSS)-induced colitis. SWCNHs labeled with gadolinium oxide for quantification purposes were detected in the gastrointestinal tract and the feces of mice, but not in the blood or other bodily organs. These results indicate that the nanohorns were not absorbed into the body from the gastrointestinal tract. SWCNH absorption was not influenced by the functionalization or size control of SWCNH. Neither death nor behavioral aberrations were observed in normal mice following SWCNH administration. However, histological observation of mice with DSS-induced colitis at 24 h after oral administration of SWCNHs revealed the presence of black particles, presumed to be SWCNHs, in the inflamed areas of the colon and the cecum. Thus, SWCNHs might serve as efficacious drug delivery carriers for the treatment of ulcerative colitis.

Four carbon-based solid acid catalysts were prepared from single-walled carbon nanohorns (SWCNHs), oxidized SWCNHs (ox-SWCNHs), activated carbon (AC), and carbon black (CB) by hydrothermal sulfonation at 200 °C in an autoclave reactor. N2 adsorption analysis suggested that sulfonation treatment leads to a drastic reduction in the number of relatively large pores with diameters greater than 20 nm in the SWCNHs and ox-SWCNHs. In addition, the BET surface area of the SWCNH was doubled by this sulfonation. These structural changes were not observed in AC and CB. The acid functional group formed on these solid catalysts by sulfonation was speculated to be –SO3H, and this was analyzed by ion-exchange titration. From the results, it was found that sulfonated SWCNHs (SO3H-SWCNHs) had the highest acid density of the four sulfonated specimens, which is a desirable property for its use as a biodiesel production catalyst. Methyl palmitate, a kind of biodiesel, was produced by the esterification of palmitic acid using these four catalysts. SO3H-SWCNHs produced the highest yield and the catalytic activity was significantly higher than that using a homogeneous sulfuric acid catalyst. Repeated esterification experiments suggested that the acid sites on SO3H-SWCNHs and SO3H-ox-SWCNHs were more stable than those on SO3H-AC and SO3H-CB.

Using the first realistic model of single walled carbon nanohorn and molecular simulation data we show the 3D graphs relating the selectivity of CO2/CH4 separation with a surface to volume ratio of a nanohorn, the total mixture pressure and the mole fraction of CO2 in the bulk phase. It is proved that surface to volume ratio is a crucial parameter determining the selectivity. Finally, the equation is proposed, making possible to predict the selectivity of a nanohorn for separation of CO2/CH4 mixture.

A study of synthesis of multi-walled carbon nanotubes (MWNTs) and carbon sphere and also their electrochemical performance for the storage hydrogen gas has been presented. The structure and the morphology of carbon nanostructures have been investigated using X-ray diffraction, scanning electron microscopy, transmission electron microscopy. Furthermore, the electrochemical hydrogen adsorption properties of MWNTs and carbon spheres were elucidated by galvanostatic charge/discharge and cyclic voltammetric measurements. The electrochemical results demonstrated that carbon spheres synthesized from sucrose and starch exhibited hydrogen adsorption of ∼0.9 and 1 wt% respectively. Whereas, the multiwalled carbon nanotubes have exhibited hydrogen adsorption of ∼1.2 wt%.

The degradation behavior of porous scaffolds plays an important role in the synthesis of new tissue. In this study, three-dimensional hybrid porous scaffolds of chitosan (CS) comprised of nanostructured carbon (graphene oxide (GO) and single-walled carbon nanohorns (SWCNH)) were prepared by freeze-drying method. In-vitro degradation behavior of scaffolds was investigated up to 8 weeks in phosphate buffer saline (PBS) solution at 37 °C. The characteristics of scaffolds explored as a function of degradation time include crystalline structure, pore morphology, molecular weight, and wet/dry weight. The pH value of the PBS solution during degradation was also monitored. The study demonstrates for the first time that hybrid chitosan scaffolds with nanostructured carbon (GO and SWCNH) are potentially more stable than pure chitosan scaffolds during the time period required for tissue regeneration. The stability of hybrid scaffolds is attributed to nanostructured carbon that was processed with the objective that it is present in a robust manner via a highly cross-linked dense network structure. The chemical structure of chitosan was disrupted within a short period of two weeks, while disruption occurred in hybrid scaffolds after eight weeks. This was accompanied by a weight loss of ∼28% in pure chitosan and ∼20% in hybrid scaffolds. Furthermore, the degraded products were of low molecular weight in pure chitosan and high molecular weight in hybrid chitosan scaffolds. This led to significant decrease in the pH of solution to ∼6.2 in pure chitosan and to ∼7.2 in hybrid scaffolds. The observations clearly underscore that the introduction of GO and SWCNH via cross-link mechanism in CS is a potentially viable approach to tune the degradation rate of hybrid scaffolds in tissue engineering.

Nitrogen-doped single-walled carbon nanohorns (N-SWCNHs) have been synthesized by a flowing nitrogen assisted arc discharge method at atmospheric pressure in a tubular reactor. X-ray diffraction and thermogravimetric analysis have revealed their high quality. Scanning electron microscopy and transmission electron microscopy examinations have shown that N-SWCNHs have typical spherical structure with a diameter of 40–80 nm. Oxidation treatment suggests the opening of cone-shaped caps of N-SWCNHs. The FT-IR and X-ray photoelectron spectroscopy analysis indicate that most of the nitrogen atoms are in N-6, N-5, and triple-bonded CN bonding configuration present at the defect sites or the edges of graphene layers.

Amphiphilic lipid–poly(ethylene glycol) (LPEG) is widely used for the noncovalent functionalization of graphene nanomaterials (GNMs) to improve their dispersion in aqueous solutions for biomedical applications. However, not much is known about the detachment of LPEGs from GNMs and macrophage uptake of dispersed GNMs in relation to the alkyl chain coverage, the PEG coverage, and the linker group in LPEGs. In this study we examined these relationships using single walled carbon nanohorns (SWCNHs). The high coverage of PEG rather than that of alkyl chains was dominant in suppressing the detachment of LPEGs from SWCNHs in protein-containing physiological solution. Correspondingly, the quantity of LPEG-covered SWCNHs (LPEG-SWCNHs) taken up by macrophages decreased at a high PEG coverage. Our study also demonstrated an effect of the ionic group in LPEG on SWCNH uptake into macrophages. A phosphate anionic group in the LPEG induced lower alkyl chain coverage and easy detachment of the LPEG, however, the negative surface charge of LPEG-SWCNHs reduced the uptake of SWCNHs by macrophages.