Enhanced Photocatalytic Activity of SiC-Based Ternary Graphene Materials: A DFT Study and the Photocatalytic Mechanism.

A graphene-like semiconductor composite is one of the most promising photocatalyst that does not use noble metals. These composites have excellent photocatalytic properties and have attracted great attention for water splitting. Here, a facile method called the hydrothermal method was used to prepare graphene oxide (GO)/SiC/MoS2 composites. Under visible-light irradiation, the GO/SiC/MoS2 composite had excellent photocatalytic production of hydrogen from water splitting. In particular, the catalyst added 8 wt % of Mo weight yielded the highest quantum of 20.45% at 400-700 nm of wavelength. A positive synergistic effect between the layered GO and MoS2 components contributed to the enhanced photoactivity of the SiC particles. The synergistic effect reduced the recombination of photogenerated holes and electrons, enhanced the rate of electron transfer, and provided more reaction active sites for water splitting. The interactions among SiC, GO, and MoS2 were investigated using a density functional theory. The calculations showed that the relative positions between graphene only slightly affect the stability of the interface, and the MoS2 layers have a great influence. The photocatalytic mechanism was also discussed, and electron transfer was predicted.

A simple FRET system using two-color CdTe quantum dots assisted by cetyltrimethylammonium bromide and its application to Hg(II) detection.

In this study, we developed a novel simple fluorescence resonance-energy transfer (FRET) system between two-color CdTe quantum dots (QDs) assisted by cetyltrimethylammonium bromide (CTAB). Mercaptopropionic (MPA)-capped CdTe QDs serving as both donors and acceptors were successfully synthesized by changing the refluxing time in aqueous solution. CTAB micelles formed in water and minimized the distance between the donors and acceptors significantly by electrostatic interactions, improving FRET efficiency. Several factors that affected the fluorescence spectra of the FRET system were investigated. The prepared FRET system was feasible as an effective fluorescent probe to detect Hg(II) in aqueous solution. At pH 7.0, a linear relationship between the quenched fluorescence intensity of orange-emitting acceptors (QDs(A) ) and Hg(II) concentration was acquired in the range 5-250 nmol/L with a detection limit of 1.95 nmol/L. The developed method showed excellent analytical performance for Hg(II) with high sensitivity and acceptable selectivity, reproducibility and stability. This finding indicated that the method has a promising potential application for environmental monitoring. This study demonstrated the great promise of QDs for expedient, low-cost and high-sensitivity detection of Hg(II).

A simply triggered peptide-based hydrogel as an injectable nanocarrier of tanshinone IIA and tanshinones.

An easily self-assembled and gelated octa-peptide FHFDFHFD was chosen as a novel drug delivery system (DDS) for both tanshinone IIA and total tanshinone extract. The DDS showed increased loading capacity, sustained drug release and better anticancer capability. Our research proved that a hydrogel DDS of other traditional Chinese medicines is possible.

Overcoming multidrug resistance by a combination of chemotherapy and photothermal therapy mediated by carbon nanohorns.

Multidrug resistance (MDR) is a major obstacle to cancer chemotherapy due to the overexpression of P-glycoprotein (P-gp). Herein, etoposide (ETO) was loaded onto oxidized carbon nanohorns (oxCNHs), which were modified by polyethylene glycol (PEG) and further functionalized with the targeting ligand P-gp monoclonal antibody (PA) in an attempt to overcome MDR. The obtained drug delivery system (ETO@oxCNHs/PEG-PA) showed high drug loading efficiency, enhanced drug release under laser irradiation, improved cellular uptake and increased therapeutic effect both in vitro and in vivo. In addition, NIR laser irradiation had a synergistic effect on overcoming MDR. The MDR-overcoming mechanism could be the efficient cellular uptake, enhanced drug release and reduced drug efflux by P-gp. These results demonstrated that ETO@oxCNHs/PEG-PA could be a promising drug delivery system for cancer MDR reversion.

Dual-function fluorescent probe for cancer imaging and therapy.

To date, several fluorescent probes modified by a single targeting agent have been explored. However, studies on the preparation of dual-function quantum dot (QD) fluorescent probes with dual-targeting action and a therapeutic effect are rare. Here, a dual-targeting CdTe/CdS QD fluorescent probe with a bovine serum albumin-glycyrrhetinic acid conjugate and arginine-glycine-aspartic acid was successfully prepared that could induce the apoptosis of liver cancer cells and showed enhanced targeting in in vitro cell imaging. Therefore, the as-prepared fluorescent probe in this work is an efficient diagnostic tool for the simultaneous detection of liver cancer and breast cancer cells.

Nanoparticle-enhanced electrical impedance detection and its potential significance in image tomography.

The conductivity and permittivity of tumors are known to differ significantly from those of normal tissues. Electrical impedance tomography (EIT) is a relatively new imaging method for exploiting these differences. However, the accuracy of data capture is one of the difficult problems urgently to be solved in the clinical application of EIT technology. A new concept of EIT sensitizers is put forward in this paper with the goal of expanding the contrast ratio of tumor and healthy tissue to enhance EIT imaging quality. The use of nanoparticles for changing tumor characteristics and determining the infiltration vector for easier detection has been widely accepted in the biomedical field. Ultra-pure water, normal saline, and gold nanoparticles, three kinds of material with large differences in electrical characteristics, are considered as sensitizers and undergo mathematical model analysis and animal experimentation. Our preliminary results suggest that nanoparticles are promising for sensitization work. Furthermore, in experimental and simulation results, we found that we should select different sensitizers for the detection of different types and stages of tumor.