Using nanomaterials to develop multimodal systems has generated cutting-edge biomedical functions. Herein, we develop a simple chemical-vapor-deposition method to fabricate graphene-isolated-Au-nanocrystal (GIAN) nanostructures. A thin layer of graphene is precisely deposited on the surfaces of gold nanocrystals to enable unique capabilities. First, as surface-enhanced-Raman-scattering substrates, GIANs quench background fluorescence and reduce photocarbonization or photobleaching of analytes. Second, GIANs can be used for multimodal cell imaging by both Raman scattering and near-infrared (NIR) two-photon luminescence. Third, GIANs provide a platform for loading anticancer drugs such as doxorubicin (DOX) for therapy. Finally, their NIR absorption properties give GIANs photothermal therapeutic capability in combination with chemotherapy. Controlled release of DOX molecules from GIANs is achieved through NIR heating, significantly reducing the possibility of side effects in chemotherapy. The GIANs have high surface areas and stable thin shells, as well as unique optical and photothermal properties, making them promising nanostructures for biomedical applications.

We have synthesized a nanostructure with a platinum (Pt) nanocrystal core and a few-layer graphene shell. This graphene-encapsulated Pt nanocrystal (GPN) was fabricated through a simple chemical vapor deposition (CVD) method. After investigating the electrocatalytic activities of GPNs, their ability to act as a relatively good fuel cell catalyst was confirmed. Furthermore, to further improve their catalytic activity, a plasma-assisted nitrogen doping method was developed, and the nitrogen-doped grapheneencapsulated Pt nanocrystal (N-GPN) also demonstrated efficient electroactivities, in fact much higher than those reported for conventional Pt-graphene composite catalysts due to their small particle diameter, uniform size distribution, sufficient graphene-Pt contact, and new generation of activation sites after nitrogen doping. This simple and efficient approach could also be extended to the preparation of other alloy nanocrystals coated with a graphene shell for electrocatalytic or electrochemical sensor applications.

BackgroundAssociations between serum cadmium and diabetes had been reported in previous studies, however there was still considerable controversy regarding associations. Studies in general population that investigated the effects of serum cadmium on diabetes were currently lacking. We designed this cross-sectional study among U.S. adults under high and low cadmium exposure to assess associations between serum cadmium and diabetes.MethodsThis cross-sectional study analyzed 52,593 adults who aged more than 20 years and participated in the National Health and Nutrition Examination Survey (NHANES), 1999–2020. The missing values and extreme values in the covariables were filled by multiple interpolation. Univariate logistics regression, multivariate logistics regression and smooth fitting curves were used to analyze the association between serum cadmium and diabetes. Simultaneously, sensitivity analysis was carried out by converting the serum cadmium from continuous variable to categorical variable. The stratification logistics regression model was used to analyze whether there were special groups in each subgroup to test the stability of the results.ResultsIn this cross-sectional study, serum cadmium levels were negatively correlated with the occurrence of diabetes in the low serum cadmium exposure group (OR = 0.811, 95% CI 0.698, 0.943; P = 0.007). There was no association between serum cadmium level and the occurrence of diabetes in the high serum cadmium exposure group (OR = 1.01, 95% CI 0.982, 1.037; P = 0.511). These results were consistent across all the subgroups (P for interaction >0.05).ConclusionSerum cadmium was negatively associated diabetes among the representative samples of the whole population in the United States under the normal level of serum cadmium exposure. However, there was no association between serum cadmium level and the occurrence of diabetes in the high serum cadmium exposure group. This study promoted an update of new preventative strategy targeting environment for the prevention and control of diabetes in the future.

In this work, we fabricate an efficient and stable photocatalyst system which has superior recyclability even under concentrated acidic conditions. The photocatalyst is prepared by assembling magnetic graphitic nanocapsules, titania (TiO 2 ) and graphene oxide (GO) into a complex system through - stacking and electrostatic interactions. Such catalytic complex demonstrates very high stability. Even after dispersal into a concentrated acidic solution for one month, this photocatalyst could still be recycled and maintain its catalytic activity. With methyl orange as the model molecule, the photocatalyst was demonstrated to rapidly decompose the molecules with very high photocatalytic activity under both concentrated acidic and neutral condition. Moreover, this photocatalyst retains approximately 100 wt% of its original photocatalytic activity even after multiple experimental runs, of magnetic recycling. Finally, using different samples from natural water sources and different dyes, this GO/magnetic graphitic nanocapsule/TiO 2 system also demonstrates its high efficiency and recyclability for practical application.