Porphyrin COF and its mechanical pressing-prepared carbon fiber hybrid membrane for ratiometric detection, removal and enrichment of Cd2.

A nitrogen (N), oxygen (O)-rich porphyrin-based covalent organic framework (COF), in which interlayer porphyrin molecules are vertically stacked, is prepared and characterized. As-prepared N,O-rich TpTph COF shows a high adsorption capacity for Cd2+ due to the abundant coordination sites. More interesting, it is found that the formation of COF enlarges the porphyrin ring center space, thus facilitating the Cd2+coordination, and the resulting optical signal changes make the ratiometric detection of Cd2+ possible. Furthermore, using carbon fiber (CF) filaments, which are obtained from low cost and easy-to-obtain actived carbon mask, as support, porphyrin COF-based CF@TpTph membrane is prepared through in-situ growth of COF on the support followed by simple mechanical pressing. The CF@TpTph membrane is demonstrated to work well for both Cd2+ removal and enrichment from soil and water samples, and shows the advantages of ease of handling, robust stability, reduced secondary pollution risk to samples, and good reusability. This work provides a powerful tool for Cd2+ removal and enrichment, exhibits that preparing porphyrin-based COFs is a feasible way to promote the interactions between porphyrin ring and Cd2+, and demonstrates that mechanical pressing is a promising strategy for the design of COF-based monolithic materials to promote the practical applications of COFs.

Separation and purification of the antioxidant compounds, caffeic acid phenethyl ester and caffeic acid from mushrooms by molecularly imprinted polymer.

Caffeic acid phenethyl ester (CAPE) and caffeic acid (CA), two naturally occurring phenolic antioxidants, have been reported to have a diversity of biological activities. In this investigation, a novel approach to separate and enrich CAPE and CA from 25 species of mushrooms using molecularly imprinted polymers (MIPs) as the sorbent material is reported. The MIPs were synthesized using CAPE as the template, and its adsorption behavior was investigated in detail. In comparison with C18-solid phase extraction (SPE), MIP-SPE displayed high selectivity and good affinity for CAPE and CA. The antioxidant potential of the mushroom extracts, before and after preconcentration using MIPs, was assayed by inhibition of erythrocyte hemolysis and lipid peroxidation. Application of MIPs with a high affinity toward CAPE and CA provides a novel method for obtaining active compounds from natural products.