Properties evaluation and separation application of naringin-imprinted polymers prepared by a covalent imprinting method based on boronate ester

Naringin-templated magnetic molecularly imprinted polymers for selective quercetin extraction from onion peel

A Magnetic Molecularly Imprinted Polymer (MMIP) was developed using naringin as template molecule, acrylamide as functional monomer and polymerized by ultrasound irradiation for the adsorption of naringin. In an unexpected turn of results, the selectivity study unveiled that the synthesized MMIP exhibited a higher affinity for quercetin over naringin. Given this high selectivity, adsorption isotherm and kinetic studies were conducted for both quercetin and naringin. The adsorption isotherm indicated multilayer adsorption of the adsorbate on the adsorbent. The kinetic study showed better agreement with the pseudo-second-order kinetic model. The maximum adsorption capacity of 7.2 mg/g was achieved for quercetin at 50 mg/L and 4.9 mg/g was attained for naringin at the same concentration. Furthermore, quercetin quantification was performed by coupling MMIP with HPLC-UV, with method validation revealing the limits of detection (LOD) and quantification (LOQ) for quercetin. Additionally, agro-industrial waste onion peel, enriched with phenolic compounds such as quercetin, was subjected to solid-phase extraction using MMIP for the purification of quercetin.

Preparation of boronate-functionalized surface molecularly imprinted polymer microspheres with polydopamine coating for specific recognition and separation of glycoside template

A facile strategy based on the boronate affinity and polydopamine coating was proposed for the preparation of surface molecularly imprinted polymer microspheres using naringin as the glycoside template. The poly(methacrylic acid-co-methyl methacrylate-co-ethyleneglycol dimethacrylate) microspheres were firstly synthesized as inner cores by suspension polymerization method, and then functionalized with 3-aminophenylboronic acid. The imprinted shell layer was obtained by self-polymerization of dopamine on the surface of boronic acid-functionalized polymer microspheres after reversible immobilization of naringin. The resultant surface molecularly imprinted microspheres showed good imprinting efficiency and recognition specificity toward the template molecule in aqueous environment. The isothermal and kinetic adsorption behaviors of the polymers were investigated. The results showed that the covalent surface imprinted microspheres possessed homogeneous recognition sites, strong adsorption affinity, and rapid rebinding kinetics. In addition, the surface imprinted microspheres were utilized as the sorbents of solid phase extraction to successfully separate and enrich naringin from Citri Grandis extract, and the recovery of naringin in eluting solution reached 84.4%.

Hydrophilic surface molecularly imprinted naringin prepared via reverse atom transfer radical polymerization with excellent recognition ability in a pure aqueous phase

An easy and highly efficient method using hydrophilic surface molecularly imprinted polymers (SMIPs) for the selective recognition of naringin from pure aqueous solution was developed.

Boronate affinity materials for separation and molecular recognition: structure, properties and applications

Boronate affinity materials, as unique sorbents, have emerged as important media for the selective separation and molecular recognition of cis-diol-containing compounds. With the introduction of boronic acid functionality, boronate affinity materials exhibit several significant advantages, including broad-spectrum selectivity, reversible covalent binding, pH-controlled capture/release, fast association/desorption kinetics, and good compatibility with mass spectrometry. Because cis-diol-containing biomolecules, including nucleosides, saccharides, glycans, glycoproteins and so on, are the important targets in current research frontiers such as metabolomics, glycomics and proteomics, boronate affinity materials have gained rapid development and found increasing applications in the last decade. In this review, we critically survey recent advances in boronate affinity materials. We focus on fundamental considerations as well as important progress and new boronate affinity materials reported in the last decade. We particularly discuss on the effects of the structure of boronate ligands and supporting materials on the properties of boronate affinity materials, such as binding pH, affinity, selectivity, binding capacity, tolerance for interference and so on. A variety of promising applications, including affinity separation, proteomics, metabolomics, disease diagnostics and aptamer selection, are introduced with main emphasis on how boronate affinity materials can solve the issues in the applications and what merits boronate affinity materials can provide.