Fabrication of superstable gold nanorod-carbon nanocapsule as a molecule loading material

In this work, we fabricated a monodisperse nanocomposite by coating gold nanorods(Au NRs) with a layer of biocompatible, stable carbon, obtaining Au NR@Carbon core–shell nanocapsules, which without any functionalization could be used as a molecule loading material due to its high surface areas. In this system, the Au NR core had a high-absorption cross section for conversion of near-infrared light to heat, which could be explored for local hyperthermia. The carbon shell, which was biocompatible and stable even under concentrated acidic and alkaline conditions, was able to adsorb molecules with p–p interactions or electrostatic interactions. In comparison with Au NR@Si O2, Au NR@Carbon nanocapsules demonstrate the following merits:(1) simple and green synthesis method,(2) far more stable with respect to high-temperature stability and(3) larger molecule loading capacity,which indicate great potential in the biomedical applications.

Stable and unique graphitic Raman internal standard nanocapsules for surface-enhanced Raman spectroscopy quantitative analysis

Graphitic nanomaterials have unique, strong, and stable Raman vibrations that have been widely applied in chemistry and biomedicine. However, utilizing them as internal standards （ISs） to improve the accuracy of surface-enhanced Raman spectroscopy （SERS） analysis has not been attempted. Herein, we report the design of a unique IS nanostructure consisting of a large number of gold nanoparticles （AuNPs） decorated on multilayered graphitic magnetic nanocapsules （AGNs） to quantify the analyte and eliminate the problems associated with traditional ISs. The AGNs demonstrated a unique Raman band from the graphitic component, which was localized in the Raman silent region of the biomolecules, making them an ideal IS for quantitative Raman analysis without any background interference. The IS signal from the AGNs also indicated superior stability, even under harsh conditions. With the enhancement of the decorated AuNPs, the AGN nanostructures greatly improved the quantitative accuracy of SERS, in particular the exclusion of quantitative errors resulting from collection loss and non-uniform distribution of the analytes. The AGNs were further utilized for cell staining and Raman imaging, and they showed great promise for applications in biomedicine.

Fabrication of GO/magnetic graphitic nanocapsule/TiO_2 assemblies as efficient and recyclable photocatalysts

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(Ti O2) and graphene oxide(GO) into a complex system through π-π 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 is 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/Ti O2 system also demonstrates its high efficiency and recyclability for practical application.