Antimicrobial activity of CdS and Ag2S quantum dots immobilized on poly(amidoamine) grafted carbon nanotubes

Abstract

Herein we report the design of antimicrobial nanohybrids, f-MWCNTs-CdS and f-MWCNTs- Ag2S developed by covalent grafting of cationic hyperbranched dendritic polyamidoamine (PAMAM) onto multiwalled carbon nanotubes (MWCNTs) and successive deposition of CdS and Ag2S quantum dots (QDs). The CdS and Ag2S QDs were in-situ deposited on PAMAM grafted MWCNTs instead of anchoring the pre-synthesized QDs. The fourth generation, amine terminated hyperbranched PAMAM was grafted on MWCNTs, which was achieved through repetitive reactions of Michael addition of methylmethacrylate to the surface amino groups and amidation of terminal ester groups with ethylenediamine. The covalent grating of PAMAM onto MWCNTs and the consecutive conjugation of CdS and Ag2S QDs was characterized using Fourier transform infrared spectroscopy, elemental analysis, powder X-ray diffraction, Raman spectroscopy, transmission electron microscopy and energy dispersive spectroscopy. The antibacterial activity of f-MWCNTs-CdS and f-MWCNTs-Ag2S nanohybrids was evaluated against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus and the results were compared with the activity of carboxylated MWCNTs, PAMAM grafted MWCNTs, PAMAM dendrimer, and CdS and Ag2S QDs. It was found that the germicidal action of MWCNTs was enhanced by grafting of PAMAM, which was further improved with immobilization of CdS and Ag2S QDs.

RETRACTED: Synthesis and characterization of silver sulfide nanoparticles for photocatalytic and antimicrobial applications

“…The present study we report the efficient bactericidal property of Ag 2 S NPs without making any hybrid form. According to Neelgund et al [29] the growth inhibition was 48% and 85.2% for S. aureus and E. coli respectively when the cells were treated with Ag 2 S QDs. The variation in growth inhibition may be due to the variation of strain used in the antibacterial experiments.…”

Single-step, size-controlled synthesis of colloidal silver nanoparticles stabilized by octadecylamine

“…The surface plasmon resonance (SPR) and large effective scattering cross section of individual silver nanoparticles make them ideal candidates for molecular labeling [11], where phenomena such as surface-enhanced Raman scattering (SERS) can be exploited. In addition, the strong toxicity that silver exhibits in various chemical forms to a wide range of microorganisms is very well known [12,13], and silver nanoparticles, silver chalcogenides and their nanocomposites have shown to be promising antimicrobial agents and photocatalysts [14][15][16][17][18].…”

Synthesis and Catalytic Applications of Multi‐Walled Carbon Nanotube–Polyamidoamine Dendrimer Hybrids

“…Two main strategies are commonly used for the immobilization of dendrimers on CNTs, namely the “grafting from” and “grafting to” approaches. In the first case, the dendrimers are grown sequentially in situ on the surface . The main drawback of this methodology is that the conversion at each step of dendrimer growth is not complete and therefore a mixture of dendrimers is present on the final surface.…”

“…In the first case, the dendrimers are grown sequentially in situ on the surface. [14,34,[42][43][44][45][46][47][48][49][50][51][52][53][54][55][56] The main drawback of this methodology is that the conversion at each step of dendrimer growth is not complete and therefore am ixture of dendrimers is present on the final surface. In the latter case, af ully grown dendrimeric structurei sa ttached directly on the nanotube.…”