Monitoring the inorganic chemical reaction by surface-enhanced Raman spectroscopy: A case of Fe³âº to Fe²âº conversion.

Monitoring the process of organic chemical reactions to study the kinetics by surface-enhanced Raman spectroscopy (SERS) is currently of immense interest. However, monitoring the inorganic chemical reaction is still an extremely difficulty for researchers. This study exactly focused on the monitor of inorganic chemical reaction. Capillary coated with silver nanoparticles was introduced, which was an efficient platform for monitoring reactions with SERS due to the advantages of sensitivity and excellent reproducibility. The photoreduction of [Fe(phen)3](3+) to [Fe(phen)3](2+) was used as model reaction to demonstrated the feasibility of SERS monitoring inorganic chemical reaction by involving in metal-organic complexes. Moreover, the preliminary implementation demonstrated that the kinetics of photoreduction can be real-time monitored by in situ using the SERS technique on a single constructed capillary, which may be useful for the practical application of SERS technique.

Sensitively monitoring photodegradation process of organic dye molecules by surface-enhanced Raman spectroscopy based on Fe3O4@SiO2@TiO2@Ag particle.

Photodegradation of organic dye molecules has attracted extensive attention because of their high toxicity to water resources. Compared with traditional UV-visible spectroscopy, SERS technology can reflect more sensitively the catalytic degradation process occurring on the surface of the catalysts. In this paper, we report the synthesis and structure of Fe3O4@SiO2@TiO2@Ag composite, which integrates SERS active Ag nanostructure with catalytically active titania. The degradation of the typical dye molecule crystal violet (CV), as an example, is investigated in the presence of the as-prepared Fe3O4@SiO2@TiO2@Ag composite structure, which exhibits high catalytic activity and good SERS performance. At the same time, renewable photocatalytic activity was also investigated.

[Research on endothelialization of artificial vascular grafts].

Endothelialization of artificial vascular graft is considered as one of the most promising methods to improve its antithrombotic ability and long-term patency. Endothelialization of artificial vascular graft includes harvesting endothelial cells, choosing some materials with better compliance and seeding endothelial cells. The methods such as immobilization of extracellular matrix protein and growth factor to substrates, stimulation of chronic in vitro shear stress for endothelial cell retention on artificial vascular graft in bioactor, genetic modificatioin of ECs, and changes of electric charge of ECs are used to increase the adherence ability of endothelial cells. This paper reviews the process of endothelialization of artificial vascular graft and makes brief comments on the methods of endothelialization of artificial vascular graft.

Grafting reaction of poly(D,L)lactic acid with maleic anhydride and hexanediamine to introduce more reactive groups in its bulk.

Bioactivity of biomaterials was a new requirement, especially in tissue engineering and drug delivery. As a traditional used biomaterial, polylactide (PLA) had no bioactivity, of course, and it still had few reactive groups to introduce some bioactive molecules in its bulk. Here, we want to introduce carboxyl groups and amino groups in the side chain of PLA to get more reactive groups for incorporating bioactive molecular later and to maintain the structure of main chain to keep its biodegradability, and to settle the acidity of PLA during hydrolysis at the same time. It was performed as follows: first, maleic anhydride was covalently grafted onto the side chain of PLA by a free radical reaction at 100 degrees C for 20 h with BPO as the initiator. Then, by amidation with a maleic anhydride group on PLA at room temperature, hexanediamine was incorporated. The resulting polymers have been characterized via GPC, (13)C NMR, DSC, and TGA. The graft ratio was tested by titration. The pH changes during hydrolysis in 0.1 M PBS with pH 7.4 of PLA, MPLA, and HPLA were investigated. All the results showed that this research has grafted maleic anhydride and then hexanediamine in the bulk of PLA. The molecular weight degradation during reaction was less than 20%. The graft ratios of were 2.68, 2.36, and 1.86%, respectively in 5, 10, and 20% raw MA in MPLA; and the anhydride groups grafted in MPLA can completely react with hexanediamine at room temperature. The pH value of HPLA remained neutral within 12 weeks' hydrolysis compared with the resulted acidity of PLA and MPLA.