Today cancer is one of the most life-threatening diseases in the world. The conventional cancer therapies, including surgery, chemo- and radiation therapies, have some disadvantages, such as limited efficiency and significant side effects. It is necessary to develop new therapeutic treatments. Herein, we integrated the targeted photocatalytic and chemotherapy in a multifunctional drug-delivery platform. The aptamer-functionalized ZnO nanoparticles (NPs) were successfully synthesized. The anti-cancer drug was loaded in the aptamer–ZnO NP system. In vitro cell cytotoxicity experiments showed that combined therapy had a higher rate of death of cancer cells compared to that of single photocatalytic or chemotherapy. Furthermore, aptamer-functionalization could greatly increase the accumulation of nanoparticles within cancer cells and lead to better therapeutic effects. The results suggest that aptamer-functionalized semiconductor nanoparticles may have potential in the development of targeted photocatalytic and chemotherapy against cancer.

We have studied down-conversion photoluminescence (PL) from (Ce, Yb) co-doped “oxygen rich” silicon oxide films prepared by sputtering and annealing. The Ce3+ ∼510 nm PL is sensitive to the Ce concentration of the films and is much stronger for 3 at. % Ce than for 2 at. % Ce after annealing at 1200 °C. The PL emission and excitation spectroscopy results indicate that the excitation of Yb3+ is mainly through an energy transfer from Ce3+ to Yb3+, oxide defects also play a role in the excitation of Yb3+ after lower temperature (∼800 °C) annealing. The Ce3+ 510 nm photon excites mostly only one Yb3+ 980 nm photon. Temperature-dependent PL measurements suggest that the energy transfer from Ce3+ to Yb3+ is partly thermally activated.

In this work, we propose a method to prepare large-area, crystalline ultrathin rare-earth (RE, i.e., Eu, Yb, Er and Tb)-doped MoS₂ thin films, using magnetron sputtering and subsequent Ar + H₂ annealing. The film thickness of as-deposited samples varied from 60 to 100 nm, and decreases to be below 10 nm after annealing at 550 °C for 30 min. X-ray diffraction and Raman spectra analysis revealed that the sample films were crystallized after the annealing, which resulted in a MoS₂ crystallite size of about 4–5 nm. X-ray photoelectron spectroscopy indicated that most of the RE ions existed in the films in trivalent states. The optical bandgap of the RE-doped MoS₂ samples decreased from 1.6 eV (undoped) to 1.3 eV (Eu-doped) in the UV-vis absorption spectra. Electrical measurements showed that the electrical resistance decreased from 9.13 MΩ (undoped) to 0.34 MΩ (Yb-doped), the carrier density increased by one to two orders of magnitude and the carrier mobility decreased from 5.4 cm²/V·s (undoped) to 0.65 cm²/V·s (Yb-doped). The sign of the Hall coefficients indicated that the undoped MoS₂ and the Yb-, Tb- and Er-doped MoS₂ samples were n-type semiconductors, while the Eu-doped sample showed p-type characteristics. This study may be helpful to broaden the photoelectronic applications of these two-dimensional materials.

We studied the photoluminescence (PL) properties of (Ce + Yb) co-doped ZnO thin films as a function of high temperature annealing. The films were fabricated by magnetron sputtering. After 1000-1100°C annealing, the near band edge (NBE) emissions of the films were dozens to a hundred times stronger than that of undoped ZnO, while the Yb³⁺ emission (~980 nm) was quite weak, indicating that energy transfers from the ZnO host to Yb³⁺ ions in the films were not efficient. X-ray diffraction analysis and scanning electron microscopy observations demonstrated that the (Ce + Yb) co-doping had a large effect on the morphology and crystallinity of the films. The crystallinity enhancement of the films is considered to be the main reason for the strong NBE enhancements of the co-doped ZnO films.

We report on the photoluminescence (PL) properties of europium (Eu) and ytterbium (Yb) co-doped SiO₂ thin film. The Eu (both Eu²⁺ and Eu³⁺) PL and the Yb³⁺ PL is co-related under different temperature annealing. However, upon 1100°C anneal, the Eu PL intensity is significantly stronger than other temperatures anneal. Transmission electron microscopy, X-ray photoelectron spectroscopy and X-ray diffraction results, suggest that meta-stable Eu²⁺-related silicates (EuSiO₃) have formed in the oxide as well as the formation of Yb₂Si₂O₇.