title: 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-Ag(2)S developed by covalent grafting of cationic hyperbranched dendritic polyamidoamine (PAMAM) onto multiwalled carbon nanotubes (MWCNTs) and successive deposition of CdS and Ag(2)S quantum dots (QDs). The CdS and Ag(2)S 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 grafting of PAMAM onto MWCNTs and the consecutive conjugation of CdS and Ag(2)S QDs were 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-Ag(2)S 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 Ag(2)S 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 Ag(2)S QDs.
authors: Department of Chemistry, Prairie View A&M University, Prairie View, TX 77446, USA.
authors: Gururaj M
authors: GM
authors: Neelgund
authors: Aderemi
authors: A
authors: Oki
authors: Zhiping
authors: Z
authors: Luo
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis* / Q000494:pharmacology*; D019187:Cadmium Compounds / Q000737:chemistry; D050091:Dendrimers / Q000737:chemistry; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development; D005029:Ethylenediamines / Q000737:chemistry; D008768:Methylmethacrylates / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D011073:Polyamines / Q000737:chemistry*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000254:growth & development; D045663:Quantum Dots; D018030:Silver Compounds / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development; D013440:Sulfides / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D000900:Anti-Bacterial Agents; D019187:Cadmium Compounds; D050091:Dendrimers; D005029:Ethylenediamines; D008768:Methylmethacrylates; D037742:Nanotubes, Carbon; C104700:PAMAM Starburst; C531249:Poly(amidoamine); D011073:Polyamines; D018030:Silver Compounds; D013440:Sulfides; C034939:cadmium sulfide; C031234:ethylenediamine; C013251:silver sulfide