Electron beam mediated synthesis of photoluminescent organosilicon nanoparticles in TX-100 micellar medium and their prospective applications

Solvated electron-induced synthesis of cyclodextrin-coated Pd nanoparticles: mechanistic, catalytic, and anticancer studies

Herein, using in situ generated solvated electrons in the reaction media, a highly time-efficient, one-pot green approach has been employed to synthesize palladium (Pd) nanoparticles (NPs) coated with a molecular assembly of α-cyclodextrin (α-CD). The appearance of a shoulder peak at 280 nm in the UV-Vis absorption spectra indicated the formation of Pd NPs, which was further confirmed from their cubic phase XRD pattern. The nanomorphology varied considerably as a function of the dose rate, wherein sphere-shaped NPs (average size ∼ 7.6 nm) were formed in the case of high dose rate electron-beam assisted synthesis, while nanoflakes self-assembled to form nanoflower-shaped morphologies in a γ-ray mediated approach involving a low dose rate. The formation kinetics of NPs was investigated by pulse radiolysis which revealed the formation of Pd-based transients by the solvated electron-induced reaction. Importantly, no interference of α-CD was observed in the kinetics of the transient species, rather it played the role of a morphology directing agent in addition to a biocompatible stabilizing agent. The catalytic studies revealed that the morphology of the NPs has a significant effect on the reduction efficiency of 4-nitrophenol to 4-aminophenol. Another important highlight of this work is the demonstration of the morphology-dependent anticancer efficacy of Pd NPs against lung and brain cancer cells. Notably, flower-shaped Pd NPs exhibited significantly higher cancer cell killing as compared to spherical NPs, while being less toxic towards normal lung fibroblasts. Nonetheless, these findings show the promising potential of Pd NPs in anticancer treatment.

Highly stable spherical shaped and blue photoluminescent cyclodextrin-coated tellurium nanocomposites prepared by in situ generated solvated electrons: a rapid green method and mechanistic and anticancer studies

Highly stable blue photoluminescent tellurium nanocomposites (Te NCs) coated with a molecular assembly of α-cyclodextrin (α-CD) have been prepared by using in situ generated solvated electrons (e_sol^-) in the reaction media. The methodology used is rapid and green as the preparation of colloids was over in a matter of a few seconds and no hazardous agents (reducing or stabilizing) were used. Furthermore, fine control over the size of Te NCs has been demonstrated by simply varying the absorbed irradiation dose. As a matter of fact, the anisotropic property exhibited by tellurium makes it difficult to control the phase and morphology of its nanomaterials. However, unlike the majority of the previous reports, Te NCs formed by the current approach were amorphous and spherical shaped. Another interesting aspect of this work is the cyan-blue photoluminescence (PL) exhibited by the NCs. Systematic photophysical investigations indicated bandgap radiative decay as the origin of photoluminescence. A compositional analysis indicated the presence of Te(0) along with tellurium oxides (TeO_x). TGA studies revealed the formation of a dense coating (∼55%) of α-CD molecules on the NCs. Pulse radiolysis-based studies evidenced the formation of Te-based transients by the solvated electron-induced reaction. Importantly, no interference of α-CD was observed in the kinetics of the transient species. Remarkable concentration-dependent killing was observed only in the case of cancerous cells, while no such trend was seen in normal healthy cells. This is a significant observation that can be utilized to achieve differential toxicity of Te nanomaterials in tumor versus normal cells.