Photocontrolled extraction of uric acid from biological samples based on photoresponsive surface molecularly imprinted polymer microspheres.

We aim to develop novel photoresponsive surface molecularly imprinted polymer (SIMP) microspheres, an SiO2 -SIMP, for the photocontrolled extraction of uric acid from biological samples. The SiO2 -SMIP was prepared on silica microspheres by surface polymerization and characterized by using scanning electron microscopy, transmission electron microscopy, FTIR spectroscopy, thermogravimetric analysis, nitrogen adsorption-desorption analysis, and UV-visible spectroscopy. The SiO2 -SMIP microspheres showed a photocontrolled uptake and release of uric acid in NaH2 PO4 buffer upon alternate irradiation at 365 and 440 nm. The SiO2 -SMIP microspheres were able to photocontrollably extract uric acid from complicated biological samples for concentration analysis with no significant interference encountered and it exhibited very good recognition ability and fast binding kinetics toward uric acid.

Photoresponsive surface molecularly imprinted polymer on ZnO nanorods for uric acid detection in physiological fluids.

A photoresponsive surface molecularly imprinted polymer for uric acid in physiological fluids was fabricated through a facile and effective method using bio-safe and biocompatible ZnO nanorods as a support. The strategy was carried out by introducing double bonds on the surface of the ZnO nanorods with 3-methacryloxypropyltrimethoxysilane. The surface molecularly imprinted polymer on ZnO nanorods was then prepared by surface polymerization using uric acid as template, water-soluble 5-[(4-(methacryloyloxy)phenyl)diazenyl]isophthalic acid as functional monomer, and triethanolamine trimethacryl ester as cross-linker. The surface molecularly imprinted polymer on ZnO nanorods showed good photoresponsive properties, high recognition ability, and fast binding kinetics toward uric acid, with a dissociation constant of 3.22×10(-5)M in aqueous NaH2PO4 buffer at pH=7.0 and a maximal adsorption capacity of 1.45µmolg(-1). Upon alternate irradiation at 365 and 440nm, the surface molecularly imprinted polymer on ZnO nanorods can quantitatively uptake and release uric acid.

Photocontrolled solid-phase extraction of guanine from complex samples using a novel photoresponsive molecularly imprinted polymer.

A novel photoresponsive molecularly imprinted polymer (MIP) was developed for the selective extraction of guanine from complex samples. The photoresponsive MIP was fabricated using guanine as the template, water-soluble 5-[(4-(methacryloyloxy)phenyl)diazenyl]isophthalic acid as the functional monomer, and water-soluble triethanolamine trimethacrylate as the cross-linker. The MIP displayed good selectivity toward guanine with a dissociation constant of (2.70 ± 0.16) × 10(-5) mol L(-1) in aqueous media. The density of the guanine-specific receptor sites in the MIP material was (4.49 ± 0.22)µmol g(-1). Quantitatively release and uptake of guanine by the MIP occurred with irradiation at 365 and 440 nm, respectively. The MIP could efficiently extract guanine from beer and then release it into aqueous media under photocontrol. This method could be used for selective separation and subsequent determination of a specific analytes from complex samples.