Biocompatible HA@Fe3 O4 @N-CDs hybrids for detecting and absorbing lead ion.

The trinary hydroxyapatite@Fe3 O4 @N-doped carbon dots (HA@Fe3 O4 @N-CDs) hybrids were prepared by one-pot hydrothermal approach and utilized to detect and remove lead ion from aqueous solution. The structures and morphologies of as-obtained nanorod-like HA@Fe3 O4 @N-CDs hybrids were characterized by X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy measurements. These HA@Fe3 O4 @N-CDs hybrids possess good magnetism by magnetic hysteresis test and multi-colored fluorescence by the CLSM measurement. Furthermore, the as-obtained hybrids display excellent biocompatibility by MTT assay. Importantly, the trinary magnetic HA@Fe3 O4 @N-CDs hybrids as a green detector and adsorbent of Pb2+ were investigated. The influence of the different pH, the concentration of heavy metal, and the maximum adsorption capacity on removal efficiency was measured in detail. The maximum Pb2+ adsorption capacity on HA@Fe3 O4 @N-CDs hybrids is 450 mg/g. The kinetic mechanism was a pseudo-second order model, and the isotherm data was fitted well by the Langmuir isotherm and Freundlich model. Hence, the nanorod-like HA@Fe3 O4 @N-CDs hybrids could be a multifunctional material with significant potential applications in heavy metal detection and adsorption, bone tissue regeneration, magnetic therapy, and biomedicine. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2019.

Fluorescent CDs@PCL hybrids via tartaric acid, CDs-cocatalyzed polymerization.

In this paper, the environment-friendly, water-soluble carbon dots (CDs) with stable photoluminescence (PL) have been prepared via the one-step pyrolysis of lotus leaf. Then the as-prepared CDs containing abundant hydroxylic and carboxylic groups were employed as cocatalyst with tartaric acid (TA) in ring-opening polymerization (ROP) of ε-caprolactone (ε-CL). The low-toxic organic acid TA, as main catalyst, was used to catalyze the ROP of ε-CL efficiently. The fluorescent CDs@PCL hybrids were obviously hydrophobic and they exhibited an excellent biocompatibility, and biodegradability due to the existence of PCL. Therefore the hydrophobic, biodegradable and multi-color fluorescent CDs@PCL hybrids may have potential applications in biomedicine, photocatalyst, bioimaging, and environmental analysis. Furthermore the application of CDs in catalyzing and initiating polymerization reaction will exemplify the versatility of CDs in the most unexpected fields.

Rank-dependent deactivation in network evolution.

A rank-dependent deactivation mechanism is introduced to network evolution. The growth dynamics of the network is based on a finite memory of individuals, which is implemented by deactivating one site at each time step. The model shows striking features of a wide range of real-world networks: power-law degree distribution, high clustering coefficient, and disassortative degree correlation.