Combination Of Carbon Nanotubes Research Articles

Multi-walled carbon nanotubes with embedded nickel sulphide as an effective electrocatalyst for Bi-functional water splitting

Water-splitting presents a viable solution to expanding energy needs. To maximise water-splitting performance, transition metal sulphides, a very efficient electrocatalyst, have been extensively researched. It is unable to generate hydrogen (H2) and oxygen (O2) because to active sites and weak electrical conductivity. Some carbon-based materials offer superior dispersion capacities and bigger active sites for charge transfer to circumvent these restrictions. This work presents an efficient electrocatalyst combining carbon nanotubes (CNTs) and electrochemically active Nickel sulphides, Ni17S18 (NiS), synthesized by using a wet-chemical approach. The improved electrocatalytic performance of NiS@CNTs can be attributed to higher surface area and higher electrical conductivity of CNTs. Furthermore, linear-sweep voltammetry (LSV) and electrochemical impedance analysis (EIS) were also utilized for the electrochemical investigations. The addition of CNTs to NiS showed a over-potential of 330 mV at 40 mA cm−2, with a Tafel slope of 47 mV dec−1 for OER. Similarly, we have also investigated the HER activity of the as-prepared electrocatalysts at the same current density, having a over-potential of 280 mV with a Tafel slope of 102 mV dec−1.

Electrochemical performance of SnS-SnS2@CNTs composites as anode materials for Sodium ion batteries

Tin sulfide based materials are attracting attention because of excellent performance as SIBs anode. However, SnS and SnS2 suffer from severe capacity degradation during the charge/discharge process, as well as high volume expansion, which prevents superior cycling stability of SIBs. In this work, carbon nanotubes (CNTs) modified SnS-SnS2 materials were prepared by a facile one-step solvothermal approach. The constructed SnS-SnS2 heterostructures have a special internal electric field that promotes charge transfer. The combination of CNTs also prevents agglomeration of active particles and improves the capacity and cycling durability of SIBs (413 mAh·g−1 after 50 cycles).

Experimental Investigation on the Grouting Performance of Foam-CNT Composite Grouts in Vertical Inclined Fractures Under Flowing Condition

Abstract Grouting is an effective method to solve the problem of water inrush in tunnel and underground engineering. However, rock fractures are often simplified as horizontal and smooth fractures in most grouting studies, while studies on vertical inclined fractures are still rare. To investigate the diffusion law in vertical inclined fractures, a vertical inclined fracture grouting simulation device was developed. A new type of cement slurry with low weight and high flowing water resistance was developed by combining carbon nanotube (CNT) slurry with foamed cement. Physical simulation experiments were conducted to investigate various factors (initial flowing water, inclination angle, sand content, and grouting rate) on the sealing efficiency of grouting. Results show that the high foam content has a negative effect on the compressive strength of the slurry, and has a positive effect on the fluidity and water resistance. The optimum ratio of slurry is 30% foam content, 1.0% CNT content, 1.3 water/cement ratio, and 3% additive content. The inclination angle and inclination direction of the fracture have a great influence on the sealing efficiency of grouting. Foam-CNT composite grouts can meet the requirement of flowing water grouting in vertical inclined fractures.

Ultralight anisotropic Ti3C2Tx MXene/Carbon nanotube hybrid aerogel for highly efficient solar steam generation

Solar steam generation (SSG) has been considered as a promising method to produce fresh water from seawater. Due to high light absorption and excellent chemical stability, carbon nanotube (CNT) has been widely used for SSG. However, it is still challenge to simultaneously realize high water evaporation rate and energy efficiency for CNT based solar steam generator. Herein, ultralight anisotropic Ti3C2Tx MXene/carbon nanotube (A-Ti3C2Tx/CNT) aerogels are designed and fabricated for highly efficient SSG. The combination of CNT and Ti3C2Tx MXene endows the hybrid aerogel with high light absorption and effective localized surface plasmon resonance (LSPR), resuting in enhanced light-to-heat conversion efficiency. The porous structure of aerogel leads to multiple scattering and absorption, further contributing to the photothermal conversion process. Moreover, the low thermal conductivity of aerogel structure effectively reduces the heat loss to environment. Through tailoring the anisotropic channel, the A-Ti3C2Tx/CNT hybrid aerogel with average channel size of 80 μm possesses most efficient water transport due to the capillary effect and formation of intermediate water. Therefore, the A-Ti3C2Tx/CNT hybrid aerogel exhibits high average light absorption of 95.68% in the wavelength range of 200–2500 nm, excellent water evaporation rate of 2.10 kg m−2 h−1 under 1 sun irradiation (1 kW m−2) with a high energy efficiency of 93.4%, and remarkable durability with 7 days continuous water evaporation. The A-Ti3C2Tx/CNT hybrid aerogel also shows high resistance to salt crystallization due to its high salt transport flux of 1.90 kg m−2 h−1. This work offers a prospective strategy for constructing highly efficient solar steam generator with stable performance for practical application in seawater desalination.

Enhanced electrochemical performances of SrMoO4/MWCNT-PVP nanocomposites as electrocatalyst for hydrogen evolution reaction

In this work, we have successfully synthesized the cost-effective, abundant in nature and environmentally friendly SrMoO4/MWCNT-PVP by using the co-precipitation technique for hydrogen evolution reaction (HER). Prepared nanocomposites were characterized by XRD, which confirms the formation of tetragonal structure of SrMoO4 and indexed with JCPDS (01-074-3912). Raman spectra confirm the combination of SrMoO4 with carbon composite (verified by D and G band 1.02 ID/IG ratio) and its functional group was further analyzed with the help of FTIR spectra. Synthesized product morphology was characterized by using SEM and TEM images, which confirms formation of well-defined dumb-bell shaped nanostructures with the combination of carbon nanotube and also it further confirms the formation of polycrystalline nature of the material. The elemental composition was analyzed by EDS images, which confirms the occurrence of Sr, Mo, O, and C in an appropriate form with a uniform distribution, respectively. MWCNT in SrMoO4 incorporation led to decrease overpotential of 204 mV and 110 mV/dec Tafel slope of the material, which was examined by the LSV curves and Tafel plot analysis. Electrochemical impedance spectroscopy was also investigated, and it delivered the small charge-transfer resistance of 248 Ω, which further supporting the HER analysis and denoting the promising HER kinetics. Therefore, our work unlocks a new path for the properly tuned nanostructured morphology of metal oxide with carbon composite for electrochemical hydrogen evolution reaction application.

Synergistic VSV Virotherapy and Carbon Nanotube Photothermal Therapy for Osteosarcoma in Murine Models.

Wide resection is usually performed for malignant bone and soft tissue tumors, but there is often functional impairment of the affected limb. In this study, we performed virotherapy with the vesicular stomatitis virus (VSV) and photothermal therapy using carbon nanotubes (CNTs) in combination for osteosarcoma, followed by marginal excision. The possibility of local treatment of the primary tumor was then assessed. LM-8 cells (1×107) were subcutaneously implanted into 5-week-old mice to generate an in vivo osteosarcoma mouse model. Marginectomy was performed. Four groups with six mice each were created: VSV+SWCNTs group, VSV group, SWCNTs group, and an untreated group. Tumor margin resection was performed 2 weeks after tumor cell transplantation. The primary tumor volume, local recurrence, distant metastasis, and survival rate were evaluated. The combination of VSV virotherapy and CNTs photothermal therapy resulted in shrinkage of the primary tumor and reduced local recurrence after marginectomy. There was no significant difference in distant metastasis or survival rate for all groups. Combining virotherapy with VSV and CNTs photothermal therapy is useful for local treatment of osteosarcoma in murine models, possibly allowing for smaller tumor resection margins.

Nanocomposites of Ni-Co-Mn MOFs and PANI functionalized CNTs-GNPs with excellent electrochemical performance for energy storage applications

Supercapacitors, pivotal for eco-friendly energy solutions, demand efficient Ni-Co-Mn MOF-based electrodes. These electrodes, combining carbon nanotubes (CNTs), graphene nanoplatelets (GNPs), and polyaniline (PANI), were created through a facile ultrasonication-assisted solvothermal method, fostering their utility in energy storage systems. Scanning electron microscopy (SEM) reveals a distinctive flower-like morphology that facilitates faradic reactions. X-ray diffraction (XRD) and Fourier-transform infrared (FT-IR) spectroscopy confirm composition and functional group analysis. Comparative studies demonstrate the superiority of the Ni-Co-Mn/PCG (PANI-CNT-GNP) nanocomposite in charge storage over pristine Ni-Co-Mn MOF. Notably, the Ni-Co-Mn/PCG-40 nanocomposite, with 40 mg of PCGs, exhibited outstanding electrochemical performance, boasting the highest specific capacity (1238C/g @ 2 Ag), minimal internal reversibility, and excellent stability. This enhanced performance is attributed to efficient interconnected pathways and the uniform flower-like structure that aids in both electron and ion transportation. The asymmetric supercapacitor assembled from Ni-Co-Mn/PCG-40 showcased exceptional metrics: 380C/g @ 0.7 Ag specific capacity, a maximum energy density of 90 Wh/kg, a maximum power density of 17,000 W/kg, and 100 % stability over 5000 cycles. This research suggests a promising, cost-effective, and environmentally friendly supercapacitor solution for energy storage applications, addressing both pollution mitigation and energy crisis concerns.

In-situ synthesis of conductive Fe-MOFs on the carbon nanotubes/carbon cloth as high-performance catalyst for alkaline oxygen evolution

In the electrolysis of water, the efficiency is heavily constrained by the slow kinetic process of the oxygen evolution reaction (OER) at the anode. Herein, by a simple hydrothermal method for the in-situ growth of Fe3(HHTP)2 on the open three-dimensional nanostructured substrate, Co-anchored carbon nanotubes/carbon cloth (Co/CNT/CC), Fe3(HHTP)2@Co/CNT/CC was prepared and acted as an OER electrocatalyst. The combination of carbon nanotubes (CNTs) and carbon cloth not only enhanced the substrate conductivity, but also facilitated the uniform loading of Fe3(HHTP)2. The in-situ growth, on the other hand, allowed the Fe3(HHTP)2 to connect with the conductive substrate tightly, thus enhancing the stability of the interfacial contact, improving the electron transfer efficiency and providing enough catalytically active sites. In addition, the construction of self-supported electrodes could effectively avoid the use of binders and improve the stability of the composites during electrolysis. The Fe3(HHTP)2@Co/CNT/CC displayed excellent properties in alkaline electrolytes as an efficient OER catalyst, achieving a current density of 50 mA cm−2 at an overpotential of only 1.60 V and perfect stability in long-term tests. Herein, the present work provides a rational tactics for developing self-supporting electrodes with plentiful active sites and high stability to enhance the electrochemical efficiency of water splitting.

Preparation of washable and salt-resistant composites for continues solar-driven evaporation and seawater desalination based on ES nonwovens

Solar-powered interfacial evaporation is a novel and eco-friendly technology for producing fresh water from seawater. However, current interfacial evaporators are expensive to manufacture, have poor tolerance for environmental conditions, and struggle to achieve stable evaporation in highly saline solutions while also preventing salt accumulation. Therefore, the fabrication of user-friendly, long-lasting, and salt-resistant interfacial evaporators remains a significant challenge. In this study, an efficient and durable interfacial evaporator was fabricated by embedding hydroxyl dobby carbon nanotubes (CNTs) and polydopamine (PDA) onto ES nonwoven fabrics. The prepared PDA-CNT-ES (PCES) composite-evaporator exhibited excellent light absorption and hydrophilic properties, which can be attributed to the light absorption capabilities of carbon nanotubes and the hydrophilicity of PDA. The combination of CNTs and PDA coatings produced a synergistic effect, leading to an efficient photothermal performance of the evaporator surface, which resulted in a significant evaporation rate of 1.29 kg⋅m−2⋅h−1 and a solar thermal efficiency of 90.77% under 1.0 solar irradiation (1 kW⋅m−2). The PCES composites, in particular, demonstrated effective purification under various simulated seawater conditions, and the desalinated water produced met the standards for potable water. The composites exhibited remarkable durability and stability over 10 desalination cycles. These results provide new insights for applying these findings in seawater desalination and wastewater treatment.

Carbon Nanotube Network Topology-Enhanced Iontronic Capacitive Pressure Sensor with High Linearity and Ultrahigh Sensitivity.

Flexible capacitive pressure sensors with high sensitivity over a wide pressure range are highly anticipated in the fields of tactile perception and physiological signal monitoring. However, despite the introduction of microstructures on the electrolyte layer, the deformability is still limited due to the size limitation of the microstructures, making it difficult to significantly improve the sensitivity of iontronic capacitive pressure sensors (ICPSs). Here, we propose an innovative strategy of combining carbon nanotubes (CNTs) topological networks and ionic hydrogel micropyramid array microstructures that can significantly enhance the sensitivity of flexible ICPSs for ultrasensitive pressure detection. Compared with other previously reported ICPSs, the sensor developed in this work exhibits an unprecedented sensitivity (Smin > 1050 kPa-1) and a high linear response (R2 > 0.99) in a wide pressure range (0.03-28 kPa) enabled by CNT percolation networks inside the microstructred electrolyte layer. This ultrasensitive and flexible ICPS also can effectively detect pressure from a variety of sources, including sound waves, lightweight objects, and tiny physiological signals, such as pulse rate and heartbeat. This work provides a general strategy to achieve an ICPS with both broader pressure-response range and higher sensitivity, which provides a stable and efficient way for a low-cost, scalable sensor for sensitive tactile sensing in human-computer interaction applications.

Energy storage investigation of solar pond integrated with PCM and nanoparticles during winter season in Chennai

Solar energy is a highly regarded renewable energy sources that are attracting substantial attention owing to its potential to alleviate climate change and provide sustainable energy. Solar ponds are one approach to collect solar energy by capturing and storing thermal energy inside a pond. However, the effectiveness of solar ponds has been hampered by reasons such as heat loss, evaporation, and inadequate heat transmission. Researchers have investigated the use of phase change materials (PCMs) and nano-additives to improve the performance of solar ponds in order to overcome these issues.Large amounts of heat can be stored and released by substances known as phase change materials as they transition between two states. By adding PCMs into solar ponds, heat may be retained throughout the day and released at night when the sun is not shining. Alternatively, nano-additives have the potential to enhance the efficiency of a solar pond by improving the heat transfer properties of the fluid present in it.To measure the thermal efficiency of the solar pond, multiple phases of an experiment have been undertaken to establish the degree of thermal efficiency. During the experiment, various parameters were employed to measure and track the temperature variations in the lower convective zone (LCZ) of the solar pond. These measurements were recorded on a daily, weekly, and hourly basis, taking into account the depth of the solar pond as a determining factor. There was also an experiment carried out using micro PCMs and paraffin waxes (PCMs) that were combined into the matrix. In this study, nanoparticles with high thermal conductivity, such as carbon nanotubes (CNTs), and hybrid nanoparticles, such as AgTiO2, were utilized.The solar pond without phase change material (PCM) had an average temperature of 45 °C in the lower convective zone (LCZ). When PCM was added to the solar pond, the maximum temperature in the LCZ increased by 2 °C compared to the previous 24 h. Furthermore, when carbon nanotube (CNT) nanoparticles were incorporated into the solar pond with PCM at the base, the temperature was observed to be 1.3 °C higher compared to a typical solar pond that only used PCM for heat storage. In another scenario, the solar pond with PCM and a combination of CNT and AgTiO2 nanoparticles had an average temperature of 52.5 °C in the LCZ during the first week of observation.

Development of nanomodified eco-friendly thermal energy storing cementitious composite using PCM microencapsulated in biosourced encapsulation shell

This study presents the development of a thermal energy storing cementitious composite that incorporates phase change material (PCM) microencapsulated in biosourced polymer shell (m-PCM). The biodegradability of the encapsulated PCM was assessed using Nuclear Magnetic Resonance (NMR), which confirmed the high biodegradability of the m-PCM shell under specific environmental conditions. To examine the thermophysical properties of the m-PCM, Differential Scanning Calorimetry (DSC) and Thermogravimetric analysis (TGA) were performed. The DSC results revealed exothermic enthalpies of 84.7 J/g and 140.2 J/g, with associated peak temperatures of − 3.2 °C and − 22.9 °C, respectively. Subsequently, the m-PCM was incorporated into cement-based mortar at proportions of 5%, 10%, and 15% by weight of binder. Uniaxial compression tests were conducted to evaluate the effect of the m-PCM on the mechanical properties of the mortar. The results indicated a significant decrease in mechanical strength upon incorporating the m-PCM. However, this reduction in strength was mitigated by the addition of silica fume (SF) and multiwalled carbon nanotubes (MWCNTs) in combination. Furthermore, a thermal cycling test was performed to examine the behavior of the nanomodified m-PCM incorporated mortar under varying ambient conditions. The results showed that the addition of MWCNTs improved both the mechanical performance and thermal performance of the composite.

Thermal energy compensation strategy to achieve rambutan-like CoFe@C-CNTs composites with controllable cross-linked networks for broadband microwave absorption

Combining carbon nanotubes (CNTs) with dielectric/magnetic materials is an attractive strategy to obtain high-performance microwave absorbing materials. However, it remains great challenges to overcome the agglomeration of CNTs and balance magnetic components to achieve impedance matching and broadband absorption. Herein, a thermal energy compensation strategy is designed to construct rambutan-like CoFe@C-CNTs composites with excellent microwave absorption performances via a catalyst chemical vapor deposition method and the subsequent reduction process. This strategy fully utilizes the thermal energy released during the C2H2 carbonization process, allowing the cracking of C2H2 and the growth of CNTs to continue at a temperature of lower than 430 °C. By adjusting the C2H2 introduction time in the cooling process of preheated cobalt iron oxide (CoFeO) nanoparticles, the number and length of CNTs on the carbon shells covering the surface of CoFeO cores can be controlled without forming metal carbides. The abundant interfaces, defects and grain boundaries in CoFe@C-CNTs composites contribute to enhancing the polarization loss via various polarizations and relaxations. Meanwhile, the appropriate 3D conductive network constructed by properly controlled CNTs provides remarkable additional conductivity loss. Furthermore, the effective retention of magnetic components greatly improves the impedance matching of the composites and offers considerable magnetic loss. Therefore, the optimized CoFe@C-CNTs-3 composite shows an effective absorption bandwidth of 9.00 GHz with a thickness of 2.1 mm. The proposed thermal energy compensation strategy provides a novel insight into developing magnetic metal-CNTs composites with potential practical applications.

Synthesis of CNT/UiO-66-NH2 adsorbent and the selective adsorption of gallium in solution

To alleviate the supply–demand contradiction of gallium metal (Ga), this study reports a method of preparing 2-CNT/UiO-66-NH2 composite materials by combining carbon nanotubes (CNTs) with UiO-66 series metal–organic frameworks (MOFs) to improve the recovery and utilization efficiency of Ga in solution. The adsorbent material is used for selective adsorption and recovery of Ga in aqueous solutions. The physical properties of the composite adsorbent, such as morphology, structure, and elemental composition, were explored by analyzing the surface characteristics of the samples. The impacts of variables like the amount of adsorbent used, time, solution concentration, pH value, and coexisting ions on adsorption efficiency were explored during the experiment. The results indicate that ion exchange and chelation play a major role in the adsorption of Ga by 2-CNT/UiO-66-NH2, and Ga ions can be separated and recovered from the mixed solution through selective adsorption. At 313 K and pH = 8, the greatest amount of adsorption is 925.44 mg/g, and the rate at which it is absorbed can reach 99% when the adsorption time is only 1 h. The hybrid absorbent generally has a high adsorption efficiency and good selective adsorption performance for Ga, providing more efficient and economical technical assistance for the future recovery and exploitation of Ga supplies.

Combination of CNTs with Classical Drugs for Treatment in Human Colorectal Adenocarcinoma (HT-29) Cell Line.

Due to the increase in new types of cancer cells and resistance to drugs, conventional cancer treatments are sometimes insufficient. Therefore, an alternative is to apply nanotechnology to biomedical areas, minimizing side effects and drug resistance and improving treatment efficacy. This work aims to find a promising cancer treatment in the human colorectal adenocarcinoma cell line (HT-29) to minimize the viability of cells (IC50) by using carbon nanotubes (CNTs) combined with different drugs (5-fluorouracil (5-FU) and two repurposing drugs-tacrine (TAC) and ethionamide (ETA). Several CNT samples with different functional groups (-O, -N, -S) and textural properties were prepared and characterized by elemental and thermogravimetry analysis, size distribution, and textural and temperature programmed desorption. The samples that interacted most with the drugs and contributed to improving HT-29 cell treatment were samples doped with nitrogen and sulfur groups (CNT-BM-N and CNT-H2SO4-BM) with IC50 1.98 and 2.50 µmol∙dm-3 from 5-FU and 15.32 and 15.81 µmol∙dm-3 from TAC. On the other hand, ETA had no activity, even combined with the CNTs. These results allow us to conclude that the activity was improved for both 5-FU and TAC when combined with CNTs.

EMI shielding, thermal and antibacterial performances of ecofriendly castor oil–based waterborne polyurethane favored by combining carbon nanotube and cetyltrimethylammonium bromide

Many ecofriendly and antibacterial polymer-based shielding nanocomposites have been designed to address the increasingly serious issues of electromagnetic interference (EMI) pollution and antibiotic resistance. These composites contain high amounts of conductive and antibacterial material and exhibit an unsurpassed EMI shielding performance and strong antibacterial properties. However, it is extremely challenging to prepare these materials because of the formation of large aggregates coupled with the high viscosity. Herein, carbon nanotubes (CNTs) and an antibacterial surfactant (cetyltrimethylammonium bromide (CTAB)) are mixed with castor oil–based waterborne polyurethane (WPU) via ultrasonic-assisted solution mixing followed by a freeze-drying approach. Owing to the presence of CTAB, CNTs (at a concentration of 24.3 wt%) are evenly dispersed and connected to each other in the WPU matrix. This morphology and intrinsic characteristics of CNTs enable the resultant CNT/WPU composites to exhibit an excellent electrical conductivity (635.8 S/m) and thermal conductivity (0.308 W/(m·K)) as well as an incomparable shielding effectiveness (SE, 88.81 dB). Notably, the specific SE reaches 997.4 dB/cm, which exceeds those of the reported composites. Moreover, the combination of CNTs and CTAB improves the antibacterial activities of the WPU composites. Due to these merits, the resultant composites have great potential for applications in portable and wearable smart electronics. Overall, this study opens a new way toward the manufacture of ecofriendly and multifunctional polymer composites.

Mussel inspired stable underwater superoleophobic cotton fabric combined with carbon nanotubes for efficient oil/water separation and dye adsorption

Currently reported biobased superwetting cotton fabrics (CF) for wastewater purification were limited because they can only separate oil/water mixtures but cannot remove other pollutants such as dyes from wastewater. In this study, we reported a superhydrophilic and underwater superoleophobic cotton fabric (SUSCF) which was fabricated via a facile two-step method, i.e., dip-coating in poly(sodium 4-styrenesulfonate) (PSS) wrapped carbon nanotube (CNT) dispersion and subsequent in-situ deposition of polydopamine (PDA). The deposited PDA particles and coated CNT endowed CF with superhydrophilicity and underwater superoleophobicity by improving surface roughness and hydrophilicity. The obtained SUSCF showed an underwater oil contact angle of 160°, which made it an attractive water-removing material for oil/water separation with separation efficiency and water flux of higher than 99.8% and 10,834 L m-2h−1, respectively. The combination of CNT, PSS, and PDA endowed the SUSCF with outstanding cationic dye adsorption capacity, especially leading to a maximum removal ratio of 97% toward methylene blue. In addition, the SUSCF exhibited excellent stability to survive after exposure to sandpaper abrasion, boiling water, organic solvents, salt solution, and acidic/alkali erosion, due to the strong hydrogen bonds and mussel-inspired adhesion between coated components and fabric surface. The stable biobased underwater superoleophobic cotton fabric with integrated excellent oil/water separation performance and dye adsorption capacity shows great potential in wastewater purification even under some harsh conditions.

Paper Batteries: A Flexible and Multifunctional Energy Storage Technology

Abstract: Paper batteries are a new class of flexible, lightweight, and low-cost energy storage devices that have the potential to revolutionize the way we use and interact with energy. They are formed by combining carbon nanotubes with a conventional sheet of cellulose-based paper, resulting in a thin and flexible device that has a high specific energy and power density. In addition to their energy storage capabilities, paper batteries can also be used as a platform for the integration of other functional materials and devices, such as sensors, transistors, and energy harvesting elements. This makes them a versatile and multifunctional technology with a wide range of potential applications, including in portable electronic devices, smart packaging, and wearable technology. In this paper, we review the current state of the art in paper battery research and development, including the materials and fabrication methods used to create these devices, their electrochemical performance, and their potential applications. We also discuss the challenges and opportunities that lie ahead for the further development and commercialization of paper batteries.

Analysis of breast cancer biomarker HER2 based on single stranded DNA aptamer and enzyme signal amplification

In this study, we described a new electrochemical immunosensor for detecting human epidermal growth factor receptor 2 (HER2) extra-cellular domain, as a breast cancer biomarker, in human serum samples. The immunosensor uses anti-HER2 combined single walled carbon nanotubes (SWNT) to label the glassy carbon electrode (GCE) to enhance the electrochemical signal and present rich antibody domains. The biotin-labeled HER2-specific aptamers were used to recognize target HER2. Then, the streptavidin labeled alkaline phosphatase (AP) as detection probes combined the aptamers and generated electrochemical signals. AP has an excellent catalytic activity to substrate α-NP and significantly amplifies the detection signal for target HER2. Using the optimized experimental conditions, the immunosensor could response down to 0.23 pg mL−1 HER2 with a linear range from 1.0 pg mL−1 to 100 ng mL−1, and showed acceptable accuracy and reproducibility. The designed sensor was used to detect other biomolecules, and found no apparent electrochemical signal, indicating its high specificity. In addition, when the biosensor was used to analyze human serum samples, it also showed sufficient recovery rate and good precision. All the results above indicate that the developed biosensor can provide an excellent potential analysis platform in breast cancer diagnostics.

Heat Transfer of Casson Fluid in Poiseuille Flow of Carbon Nanotubes: A Power Series Approach

Combination of Carbon Nanotubes (CNTs) with Human blood as base fluid indicates the enhancement of heat transport in Poiseuille flow and this physical phenomenon could not possible in normal liquids. Usually, when blood cells get touch with external surfaces, the platelets of blood become activated and form blood clots. Therefore, we have considered blood compatible CNT, so that chosen base fluid (blood) can easily pass through it. Due to the higher thermal conductivity, CNTs play an important role to enhance the heat transport in blood flow. These features lead to the novelty of this investigation to study the heat transport of Casson fluid through CNTs in unsteady MHD free convective Poiseuille flow with thermal radiation. Such study consigns practical applications in manufacturing of drugs, biomedical and Tissue engineering, biosensor and other applications in myocardial therapy, neuronal and muscle regeneration. The non-dimensional governing equations are formulated and solved analytically through classical Perturbation Technique and the analysis of results are drawn in smooth curves via MATLAB code. Significant results for different implanted parameters are compared between SWCNT and MWCNT and their significant behaviours are plotted graphically. The obtained results indicate that Casson parameter accelerates the flow velocity for MWCNT and SWCNT. Furthermore, interesting behavior on the outlines of velocity for SWCNT and MWCNT due to the presence of Schmidt number, Peclet number and Reynolds number are detected. Comparison with previously published work has been inspected and originated excellent agreement.