Design, Synthesis and Antimicrobial Activities of New Carbon Nanotubes Derivatives

Abstract

Even though natural products or crops have been more common and popular in the recent, the chemicals without side-effects have been also addressed in various fields of industries due to possibility obtaining the large quantity and more bio-efficacy. In that context, many drugs have been developed for antibacterial activities but the over-uses of those relevant drugs have caused that microorganisms have adapted and evolved resistance against those drugs. Those lead to the researchers to focus on newly synthesized or functionalized molecules. In that context, nanotechnology, especially modified nanocarbon tubes (NCTs), are of the great interest of the various industries. Along with the current study, multi-walled carbon nanotubes (MWCNTs) were functionalized with three steps. Firstly, the carbon nanotube with a carboxylic acid tip on its surface was commercially purchased and then converted into acyl chloride, and later converted into a more reactive group. Then, the nucleophilic amino group such as diethylene triamine is bonded onto the carbon nanotube. Finally, after the carbon nanotube material with amine groups was functionalized with boric acid, carbon nanotube molecules carrying boric acid molecules were synthesized. Following modification and functionalization of MWCNTs, the newly synthesized molecules were characterized using FT-IR, SEM, TEM and XPS. After chemical characterization, the relevant molecules were screened for their anti-bacterial activities in comparison to those of well-known antibiotics. For anti-bacterial assays, molecules were tested against K. pneumoniae, E. coli, P.aeruginosa, S. aureus and B. subtilis. Concerning the findings of the antibacterial assays, concentrations of 40 and 80 μg /mL exhibited a range of activities but in parallel with those of standard antibiotics whereas the lower concentration, viz. 5, 10 and 20 μg / mL did not exhibit any activities. The highest activity was noted for 80 μg / mL, in comparison to those of antibiotics and other concentrations, against B. subtilis, with a 23 mm inhibition zone.