ABSTRACT
Molecularly imprinted solid-phase extraction to treat biological samples has attracted considerable attention. Herein, molecularly imprinted polymer (MIP) microspheres with porous structures were prepared by a combined suspension-iniferter polymerization method using capecitabine (CAP) as a template molecule. This material was subsequently used as a solid-phase extraction agent to separate and enrich drug molecules in urine samples. UV analysis revealed that methacrylate (MAA) was an ideal functional monomer, and 1H Nuclear Magnetic Resonance (1H NMR), Ultraviolet (UV), and Fourier transform-infrared (FT-IR) spectroscopic analyses were used to study the interaction forces between MAA and CAP, demonstrating that hydrogen bonding was the primary interaction force. MIPs with outstanding selectivity were successfully prepared, and the analysis of their surface morphology and chemical structure revealed a spherical morphology with small holes distributed across a rough surface. This surface morphology significantly reduced the mass transfer resistance of template molecules, providing an ideal template recognition effect. Using the molecularly imprinted solid-phase extraction method, CAP and the structural analog cytidine (CYT) were pretreated in urine samples and quantified by HPLC. The results showed that CAP and CYT recoveries reached 97.2% and 39.8%, respectively, with a limit of detection of 10.0-50.0 µg·mL-1. This study provides a novel approach to drug molecule pretreatment that can be applied in drug separation and functional materials science fields.
ABSTRACT
Inferior electrical conductivity and large volume variation are two disadvantages of metal selenides. In this work, we have designed a core-shell structure of FeSe2@C composite with low cost using facile hydrothermal method. The FeSe2particles as the 'core' and the carbon layer as the 'shell' displayed good synergistic effect that attributed to alleviate volume expansion of electrode and improving the electrical conductivity, which achieved the fast potassium storage. The core-shell structural FeSe2@C electrode achieved 286 mA h g-1at 1 A g-1over 1000 cycles with 99.8% coulombic efficiency and delivered excellent rate capacity with 273 mA h g-1at 2 A g-1, which was ascribed to dispersed FeSe2particles and the strong carbon shell coating. This work will provide the basis for the further development of the application of metal selenides in the field of flexible electrodes.
