The study of synthesis and functionalized single-walled carbon nanotubes with amide group

Novel combination of multi-walled carbon nanotubes and gold nanocomposite for photothermal therapy in human breast cancer model

Despite current medical advancements, the resistance of malignant tumours to conventional medical therapies highlights the need for innovative therapeutic techniques. Numerous studies have focused on the promising application of nanomaterials in recent years. Nanoparticles (NPs) are used to treat cancer. Plasmonic photothermal therapy (PPTT) is a cancer-ablation technique in which photon energy is rapidly converted into heat by some radiative and non-radiative events. Gold NPs (Au-NPs) and carbon nanotubes (CNTs) are plasmonic NPs with excellent thermal conductivity and their near-infrared (NIR) absorbance has several interesting qualities. Additionally, CNTs could penetrate cells. In this study, Au-NPs were used to fabricate multi-walled CNTs (MWCNTs), which could boost its efficacy in cancer treatment in accordance with PPTT. Transmission electron microscopy, field-emission scanning electron microscopy (FESEM), atomic force microscopy and FTIR were used to examine the MWCNTs made from walnut shell. Au-NPs were explored using green chemistry and MWCNT-COOAu, MWCNT-COO and MWCNT-Au were examined by Raman, EDX and FESEM techniques. The effect of MWCNT-COOAu, MWCNT-COO and MWCNT-Au at various concentrations (3.12, 6.25, 12.5 and 25 µg/mL) and irradiation time intervals (30, 60, 90 and 120 sec) by using NIR laser under λ = 1064 nm and P = 3 W on the breast cancer cell line (MCF7) was investigated. The highest temperatures for MWCNT-COO, MWCNT-COOAu and MWCNT-Au were determined to be 44.1 °C, 46 °C and 46.9 °C, respectively, which produced 61.66 %, 72 % and 85.3 % cytotoxicity, respectively, in MCF7 cell line at a concentration of 25 µg/mL and an irradiation period of 120 sec. The treatment of MCF7 cell line by photothermal therapy was found to be in a concentration- and time-dependent manner.

Amino-Functionalized Multiwall Carbon Nanotubes as Efficient Basic Catalysts for the Formation of γ-Lactams: Synthesis of N-1-Heptenyl-2-Pyrrolidinone

In this work, we prepared a series of N-functionalized carbon nanotubes by means of a process of acylation-amidation of commercial multiwall carbon nanotubes that were previously pre-oxidized with nitric acid. Three different amines, butylamine, N,N-dimethyl ethylenediamine, and ethylenediamine, were used in the process. The characterization of samples by several techniques probed the incorporation of nitrogen atoms to the carbon nanotubes, especially in the case of ethylenediamine. The solids were tested as catalysts in the synthesis of N-1-heptenyl-2-pyrrolidinone, included in the group of a γ-lactams, compounds that show important biological properties. The most active catalyst was that prepared with butylamine, which exhibited the highest S_BET and V_pore values and contained an amount of nitrogen that was intermediate between that of the other two catalysts. A yield of 60% to N-1-heptenyl-2-pyrrolidinone was achieved after 3 h at 120 °C under free-solvent conditions. This catalyst could be used in four consecutive cycles without significant activity loss.

Chitosan grafting onto single-walled carbon nanotubes increased their stability and reduced the toxicity in vivo (catfish) model

The present work was aimed to develop the tissue benign, modified acid-functionalized single-walled carbon nanotube (COOH-SWCNT) chitosan (CS) hybrid (COOH-SWCNT-CS). Chitosan-nanotube hybrids were characterized by Fourier-transform infrared spectroscopy (FTIR), Thermogravimetry Analysis (TGA), Raman spectroscopy, Emission Gun-Scanning Electron Microscopes (FEG-SEM), Transmission Electron Microscopy (TEM) and Energy-dispersive X-ray spectroscopy (EDS). Micronuclei test of blood cells, comet assay of liver tissue and histological analysis of liver and kidney tissues were conducted after different treatments to evaluate the toxicity. Fish receiving COOH-SWCNT developed more numbers of micronuclei than COOH-SWCNT-CS treatments. Similarly, more DNA damage was observed in fish injected with nanotubes alone than chitosan hybrid groups. Histological observations revealed severe liver cell damage at higher concentrations of COOH-SWCNT whereas, in COOH-SWCNT-CS, no such damage was observed. However, kidney tissue remained unaffected in all groups. The study suggests that the nanohybrid developed will be safe and useful for delivery of micro or macro biomolecules in fish and higher animals.

Effect of Functionalized Carbon Nanotubes in the Detection of Benzene at Room Temperature

In this paper, carbon nanotubes (CNTs) were functionalized by acid treatment and further functionalized with dodecylamine and were designated as CNT-carboxylic and CNT-amide, respectively. Then, functionalized CNTs produced were characterized with various methods to verify the attachment of a functional group. Performance of the functionalized CNTs in the detection of benzene gas was monitored at room temperature. The sample was dropped cast on the interdigitated transducer (IDT), and the changes in resistivity were recorded by a digital multimeter in a customized chamber under controlled humidity (∼55%) environment. Based on the findings, it showed that the functionalized CNTs provide an extra active area for interaction between the gas analyte and CNTs, thus increasing their response and improving the sensitivity of the sensing material.