In this work, a highly efficient and rapid method for simultaneously removing cationic dyes from aqueous solutions was developed by using monodispersed mesoporous silica nanoparticles (MSNs) as the adsorbents. The MSNs were prepared by a facile one-pot method and characterized by scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, and Brunauer-Emmett-Teller. Experimental results demonstrated that the as-prepared MSNs possessed a large specific surface area (about 585 m2/g), uniform particle size (about 30 nm), large pore volume (1.175 cm3/g), and narrow pore size distribution (1.68 nm). The materials showed highly efficient and rapid adsorption properties for cationic dyes including rhodamine B, methylene blue, methyl violet, malachite green, and basic fuchsin. Under the optimized conditions, the maximum adsorption capacities for the above mentioned cationic dyes were in the range of 14.70 mg/g to 34.23 mg/g, which could be achieved within 2 to 6 min. The probable adsorption mechanism of MSNs for adsorption of cationic dyes is proposed. It could be considered that the adsorption is mainly controlled by electrostatic interactions and hydrogen bonding between the cationic dyes and MSNs. As a low-cost, biocompatible, and environmentally friendly material, MSNs have a potential application in wastewater treatment for removing some environmental cationic contaminants.
Dioscorea opposita Thunb, commonly known as “yam” that has a long dietary therapy history for diabetes, is widely consumed as a botanical dietary supplement and widely cultivated in China. In this work, a method for rapid screening of α-glucosidase inhibitors from Dioscorea opposita Thunb peel extract was developed using α-glucosidase functionalized magnetic nanoparticles (αG-MNPs) as a solid phase extraction absorbent in combination with high performance liquid chromatography-mass spectrometry (HPLC-MS). Two α-glucosidase inhibitors were selectively extracted and identified as batatasin I and 2,4-dimethoxy-6,7-dihydroxyphenanthrene. Their α-glucosidase inhibitory activities (IC50 = 2.55 mM and 0.40 mM, respectively) were significantly higher than that of acarbose (as control). Taking advantage of the specificity in enzyme binding and the convenience of magnetic separation, this method has great potential for rapid and fast screening of α-glucosidase inhibitors from complex natural resources.
MIL-based molecularly imprinted polymer (MIP) nanocomposites were successfully synthesized through a simple and versatile stirring auxiliary encapsulation method. MIP as a carrier has been applied to the highly efficient selective recognition and sustained release of doxorubicin hydrochloride (DOX). The adsorption mechanism and release behavior of MIP@DOX in vitro were also discussed. Adsorption studies showed that MIP using DOX as template had specific selectivity to DOX, and its optimal drug loading efficiency reached 97.99%. The adsorption isotherm accorded with Freundlich models. The cumulative release curve showed that at the conditions of pH 5.5 and 7.4, the nanomaterials have a slow-release effect on the release of DOX. In addition, the cytotoxicity and bioactivity of MIP nanoparticles on HepG2 and HL-7702 cell lines measured by MTT assay also proved their low toxicity and biological activity. The cell activity of HepG2 and HL-7702 incubated with MIP for 24 h was 69.9% and 76.07%, respectively. These results collectively illustrated that the MIP nano-materials synthesized in this study can be efficiently employed to the drug delivery systems.
1 April 2014 in Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy