We report the synthesis of hollow Au–Ag bimetallic nanoparticles with high photothermal stability under NIR irradiation.

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In this research, we conducted a systematic evaluation of the synthesis parameters of a multi-responsive core-shell nanocomposite (Fe3O4 nanoparticles coated by poly(N-isopropylacrylamide) (PNIPAM) in the presence of chitosan (CS) (Fe3O4@PNIPAM-CS). Scanning electron microscopy (SEM) was used to follow the size and morphology of the nanocomposite. The functionalization and the coating of Fe3O4 nanoparticles (Nps) were evaluated by the ζ-potential evolution and Fourier Transform infrared spectroscopy (FTIR). The nanocomposite exhibited a collapsed structure when the temperature was driven above the lower critical solution temperature (LCST), determined by dynamic light scattering (DLS). The LCST was successfully shifted from 33 to 39 °C, which opens the possibility of using it in physiological systems. A magnetometry test was performed to confirm the superparamagnetic behavior at room temperature. The obtained systems allow the possibility to control specific properties, such as particle size and morphology. Finally, we performed vincristine sulfate loading and release tests. Mathematical analysis reveals a two-stage structural-relaxation release model beyond the LCST. In contrast, a temperature of 25 °C promotes the diffusional release model. As a result, a more in-depth comprehension of the release kinetics was achieved. The synthesis and study of a magnetic core-shell nanoplatform offer a smart material as an alternative targeted release therapy due to its thermomagnetic properties.

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Fabrication of white light-emitting nanophosphors with high luminous efficacy is an urgent need for the nextgeneration lighting industry and display systems. While rare-earth ions have been frequently utilized as dopants to fabricate semiconducting and dielectric nanophosphors, the limited abundance of rare-earth elements on our planet demands a search for suitable alternatives. Here, we report the fabrication of ZnS nanoparticles co-doped with Co 2+ and Mn 2+ transition metal ions which manifest intense near-white light emission under ultraviolet excitation. While the nanophosphors could be fabricated through a simple low-temperature two-step chemical process, both the color and intensity of their emission can be tuned just by varying the molar concentration of the two dopant ions. The variation of the emission color and its intensity in the nanophosphors due to the dopant ion concentration has been explained considering the interband energy transfer from Mn 2+ ions to Co 2+ ions and creation of deep level defect states in the host nanocrystals. The synthesis process utilized in the present work opens up the possibility of fabricating low-cost, emission-tuned, rare-earth-free nanophosphors for developing high-efficiency light-emitting devices.