Ag2S nanocrystallites deposited over polyamidoamine grafted carbon nanotubes: An efficient NIR active photothermal agent

Publication date: Available online 24 May 2019Source: Materials Chemistry and PhysicsAuthor(s): Gururaj M. Neelgund, Makobi C. Okolie, Folami K. Williams, Aderemi OkiAbstractA novel NIR (near infrared) active photothermal agent, CNTs-PAMAM-Ag2S has been synthesized by covalent grafting of polyamidoamine (PAMAM) to carbon nanotubes (CNTs) and subsequent deposition of Ag2S nanocrystallites. The potential of CNTs-PAMAM-Ag2S as a NIR active photothermal agent was preliminarily accessed by its electronic absorption spectrum measured in UV–vis–NIR region. The CNTs-PAMAM-Ag2S exhibited excellent photothermal effect and photothermal conversion efficiency of 26% under illumination with 980 nm laser, the efficiency was found to be higher than popular gold and copper based photothermal agents. Temperature attained by CNTs-PAMAM-Ag2S during measurement of its photothermal effect was 64.7 °C at 1 g/mL, which far exceeds the temperature tolerance level of cancer cells. So that CNTs-PAMAM-Ag2S could destroy the cancer cells in an effective manner. Furthermore, it was found the linear dependence of photothermal effect of CNTs-PAMAM-Ag2S over its concentration. CNTs-PAMAM-Ag2S possessed excellent stability against photo-bleaching and photo-corrosiveness. In consideration of its outstanding photothermal effect and photothermal conversion efficiency, CNTs-PAMAM-Ag2S could be a promising photothermal agent to employ in future photothermal therapy.Graphical abstract
Source: Materials Chemistry and Physics - Category: Materials Science Source Type: research