The potentials of activated carbon nanoparticles (ACNP) as anticancer drug carriers were studied. ACNP were prepared with a top-down method. ACNP-based drug delivery system of docetaxel (ACNP-DOC) was prepared with a simple absorption method and its effects were studied primarily with methyl thiazolyl tetrazolium (MTT) assay, light microscope (LM), atomic force microscope (AFM) and transmission electron microscope (TEM). The prepared ACNP were approximately globular in shape with an average size of 233 nm, which had a saturate adsorption of 195.69 mg/g at mass ratio of ACNP: DOC=5:1. The drug delivery system prepared by adsorbing of ACNP for DOC had excellent releasing profile in the simulated in vivo environment. LM observation showed that ACNP can accumulate around the cells and on the surface of cells and TEM revealed that ACNP can enter cells and nuclears. MTT test demonstrated that ACNP-DOC had inhibitive effects on the growth of A549 cells, with an IC50 of 0.79 μg/ml, significantly smaller than that of 20 μg/ml of free DOC, indicating ACNP-DOC had stronger effects than free DOC. The imaging of AFM showed that both DOC and ACNP-DOC caused significant pathological changes of the cell membrane, including rough surfaces, large grains and holes, but these pathological changes were more obvious in ACNP-DOC treated cells than those free DOC treated ones. In all of the experiments, ACNP themselves had no significant influences on A549 cells. It was concluded that ACNP could serve as a good nanocarrier for anti-cancer drug delivery to target cells and have a great potential application in antitumor chemotherapy.

The novel sensors based on TiO₂ nanotubes-supported MS (TiO₂@MS, M = Cd, Zn) are synthesized via a simple wet chemical method at room temperature. The products are characterized with transmission electron microscopy (TEM), X-ray diffraction (XRD), and photoluminescence spectrum (PL). Their optical and morphological properties indicate the interaction between the TiO₂ nanotube and MS nanoparticle. The gas-sensing properties of the obtained samples are studied. Sensors based on the TiO₂@MS core/shell heterostructures all show improved gas-sensing properties. The results reveal that the improved performance of the nanocomposites strongly depends on the specific interaction between MS and support.