Chunming Wang

Green and facile synthesis of highly biocompatible graphene nanosheets and its application for cellular imaging and drug delivery

A green and facile method for the preparation of gelatin functionalized graphene nanosheets (gelatin–GNS) was reported by using gelatin as a reducing reagent. Meanwhile, the gelatin also played an important role as a functionalized reagent to prevent the aggregation of the graphene nanosheets. The obtained biocompatible gelatin–GNS exhibited excellent stability in water and various physiological fluids including, cellular growth media as well as serum which were critical prerequisites for biomedicine application of graphene. Cellular toxicity test suggested that the gelatin–GNS was nontoxic for MCF-7 cells, even at a high concentration of 200 μg mL−1. Furthermore, the anticancer drug was loaded onto the gelatin–GNS at a high loading capacity via physisorption for cellular imaging and drug delivery. The doxorubicin/gelatin–GNS composite exhibited a high toxicity to kill MCF-7 cells and experienced a gelatin-mediated sustained release in vitro, which has the potential advantage of increasing the therapeutic efficacy. Therefore, the gelatin–GNS could be selected as an ideal drug carrier to be applied in biomedicine studies.

Highly ordered multilayered 3D graphene decorated with metal nanoparticles

Highly ordered multi-layered three-dimensional (3D) graphene structures decorated with Pd, Pt and Au metal nanoparticles are prepared and characterized. The ability to control the morphology, distribution and size of the metal nanoparticles on the 3D graphene support upon changing the electro- and electroless-deposition conditions is demonstrated. Tailor-made Pt nanostructures, with nanospike and nanoparticle shapes, are prepared using electroless deposition techniques. Au nanoflowers and nanoparticle structures and Pd nanocubes are obtained following electrodeposition onto the 3D graphene support. The deposition patterns and trends are characterized. The greatly enhanced electrocatalytic activity of the metal-NP–graphene surfaces has been illustrated in connection to voltammetric measurements of ORR and hydrogen peroxide at 3D-graphene coated with Pt and Pd nanoparticles, respectively. Such metal nanoparticles decorated multi-layer 3D graphene allows for high mass transport access and catalytic activity for a diverse range of applications, including sensor and fuel-cell technologies.

Voltammetric Behavior of Mercury(I,II) Ions at an Amide-Functionalized Humic Acids Modified Carbon Paste Electrode

Amide-functionalized humic acids (AHA) was synthetized by two step reactions, in which humic acids first reacted with thionyl chloride(SOCl2) and then reacted with ammonia liquor. The AHA was characterized by Fourier transform infrared (FTIR) spectra and elemental analysis method. The reaction properties between AHA and mercury ions(I,II) were investigated at an AI-IA chemically modified carbon paste electrode (AHA-CMCPE) using cyclic voltammetry (CV) and linear sweep stripping voltammetry (LSSV). Moreover, the binding behavior of numerous other ions at the AHA-CMCPE was also tested. In an open circuit, Both Hg-I and Hg-II were accumulated from a stirred 0.1M H2SO4 solution onto the AHA-CMCPE. The subsequent electrochemical measurement was performed in another clean supporting electrolyte of 0.5M H2SO4 Factors affecting the accumulation and electrode reaction steps were investigated and an optimized procedure for quantifying mercury was developed. Under optimized conditions, a calibration plot for mercury concentration in the range 4.98 x 10(6)-4.98 x 10(8) was obtained. The new electrode can be used to determine mercury whether in the Hg-I or Hg-II forms.

Self-propelled chemically-powered plant-tissue biomotors

Self-propelled biocatalytic motors based on plant tissues are described. The tissue motors rely on their rich catalase activity towards biocatalytic decomposition of the H2O2 fuel and generation of the bubble thrust. These biomotors obviate the need for pure enzymes, and offer a remarkably low cost, good lifetime and thermostability.

The study of antimony underpotential deposition on gold electrode and its analytical application

The underpotential deposition (UPD) of antimony(III) on gold electrode was studied by using cyclic voltammetry (CV). Based on the excellent electrochemical properties of the Au/Sb UPD system, a new method for determination of antimony was developed. In this case. a more sensitive electroanalytical technique, 1.5(th) order differential anodic stripping voltammetry (1,5(th) ODASV), was used. A solution of 0.1 mol/L HCl was selected as the supporting electrolyte. Factors affecting the Sb(III) UPD and stripping steps were investigated and an optimized analytical procedure was proposed. The calibration plots for Sb(III) concentration in the range 1,25 x 10(-8)-3.38 x 10(-7) mol/L were obtained. A detection limit of 2.1 x 10(-9) mol/L was found for a 120 second electrochemical deposition at -0.100 V while the solution was stirred magnetically at a speed of 300 rpm. For 9 successive determinations of 2.5 x 10(-8) mol/L Sb(III). relative standard deviations, RSD, of 0.55% was obtained. The developed method was applied to antimony determination in ore samples.