RESUMO
Metal oxide-based macroporous ordered double affinity molecularly imprinted polymers (D-MIPs) were developed as solid phase extraction (SPE) adsorbents for the specific identification of ovalbumin (OVA) under physiological pH conditions prior to ultraviolet visible (UV-vis) spectrophotometric detection. Herein, macroporous alumina (MA) was used as a matrix; dimercaptosuccinic acid (DMSA) and 3-aminophenylboric acid (APBA) were employed as dual-functional monomers; APBA is a self-polymerizing monomer. The effects of synthesis conditions, SPE conditions as well as selectivity, reproducibility, and reusability were studied. The co-modification of DMSA and boronate affinity renders the adsorbent exhibiting a high adsorption capacity (114.4 mg g-1) and short equilibrium time (30 min). The surface imprinting technology causes the adsorbent to have high selectivity towards OVA. The OVA recovery range is 91.1-99.6%. This study provides a promising method for the enrichment of OVA and other cis-diol-containing analytes in complex biological samples. A novel metal oxide-based macroporous ordered nanoparticle with a combination of DMSA and boronate affinity was successfully prepared for specific separation and enrichment of glycoprotein from complex biological samples.
Assuntos
Óxido de Alumínio/química , Boratos/química , Contaminação de Alimentos/análise , Glicoproteínas/análise , Polímeros Molecularmente Impressos/química , Succímero/química , Análise de Alimentos , Tamanho da Partícula , Porosidade , Propriedades de SuperfícieRESUMO
Zeolite imidazole framework-based boronic acid-functionalized metal-organic frameworks (ZIF-67@PDA@BA-Zr-MOFs) were developed as an adsorbent for solid phase extraction (SPE) of luteolin (LTL) from peanut shell samples. Herein, ZIF-67 as a support matrix, polydopamine (PDA) as a coating to introduce amino and hydroxyl groups on the matrix surface to fix metal-organic frameworks (MOFs), zirconium tetrachloride (ZrCl4) as a precursor, terephthalic acid (TPA), and 3-carboxyphenylboronic acid (3-CPBA) as the mutual organic building blocks, and 3-CPBA was also a boronate affinity functional monomer. The effects of synthesis conditions, SPE conditions, selectivity, competitivity, reproducibility, and reusability were evaluated in detail. Under the optimal conditions, the maximum adsorption capacity is 71.4 mg g-1. The utility of ZIF-67@PDA@BA-Zr-MOFs as an adsorbent for SPE of LTL is supported by the presence of the abundant pore structure, as well as the boronate affinity sites facilitated the rapid binding of the adsorbent to the template. The concentration of the extracted LTL was determined by the high-performance liquid chromatography-ultraviolet (HPLC-UV), with calibration plots being linear in the concentration range 0.05-100 mg L-1 and a limit of detection (LOD) of 0.035 mg L-1. The method was applied to determine the LTL in peanut shell samples and recovered the target analyte in the range 85.6% to 99.2% (the standard deviations are less than 3.3%, n = 3). In addition, we incorporated boronate affinity and MOFs material into an SPE system to provide a promising strategy to detect other cis-diol-containing analytes in the complex matrix.
RESUMO
Solution-processed cadmium telluride (CdTe) nanocrystal (NC) solar cells offer the advantages of low cost, low consumption of materials and large-scale production via a roll-to-roll manufacture process. Undecorated CdTe NC solar cells, however, tend to show inferior performance due to the abundant crystal boundaries within the active CdTe NC layer. The introduction of hole transport layer (HTL) is effective for promoting the performance of CdTe NC solar cells. Although high-performance CdTe NC solar cells have been realized by adopting organic HTLs, the contact resistance between active layer and the electrode is still a large problem due to the parasitic resistance of HTLs. Here, we developed a simple phosphine-doping technique via a solution process under ambient conditions using triphenylphosphine (TPP) as a phosphine source. This doping technique effectively promoted the power conversion efficiency (PCE) of devices to 5.41% and enabled the device to have extraordinary stability, showing a superior performance compared with the control device. Characterizations suggested that the introduction of the phosphine dopant led to higher carrier concentration, hole mobility and a longer lifetime of the carriers. Our work presents a new and simple phosphine-doping strategy for further improving the performance of CdTe NC solar cells.
RESUMO
A gallic acid-affinity molecularly imprinted polymer (G-MIP) was first used as an adsorbent for selective identification and capture of luteolin (LTL) in herbal medicine samples. The G-MIP was prepared by using LTL as the template, gallic acid (GA) as the functional monomer, ethylene glycol dimethacrylate (EGDMA) as the crosslinking agent, and 2,2'-azobis(2-methylpropionitrie) (AIBN) as the initiator. The properties of G-MIP were characterized by FT-IR, transmission electron microscope, scanning electron microscope, dynamic light scattering, specific surface area, and X-ray photoelectron spectrum. The adsorption conditions were optimized, and the adsorption equilibrium model and adsorption kinetics model of the adsorbent were investigated under the best experimental conditions. The saturated adsorption capacity is 1.24 mg g-1, which is not only higher than the adsorption capacity of 4-carboxyphenylboronic acid-affinity MIP adsorbent but also superior to those of many reported adsorbents for enriching of LTL. The LTL was quantified by HPLC. The linear range is 0.05-100 mg L-1, the detection limit is 0.020 mg L-1. This method was successfully applied in the selective recognition of LTL in herbal medicines with recoveries of 93.9-114.2%, and the relative standards deviations (RSDs) are 0.4-5.6%. Thus, this work provides a potential possibility and practical platform for the determination of LTL in complex matrices.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Ácido Gálico/química , Luteolina/análise , Polímeros Molecularmente Impressos/química , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Espectroscopia Fotoeletrônica , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
In this work, the boronate-affinity hollow stannic oxide based fragment template molecularly imprinted polymers (Bh@SnO2-FMIPs) were fabricated successfully. Polystyrene was used as sacrificial support, SnO2 was selected as inorganic matrix, surface imprinting using catechol as fragment template and 4-vinylphenylboronic acid as boronate-affinity functional monomer. A thin layer of poly 2-anilinoethanol (2-AE) was formed to coat the boronate-affinity hollow SnO2 surface through self-polymerization, it has strong hydrophilicity and limited residual boric acid content, avoiding non-specific binding. The hollow structure could bind to target molecules effectively and facilitate the removal of template molecules. The Bh@SnO2-FMIPs were used to extract three cis-diol polyphenols containing catechin, chlorogenic acid, and caffeic acid in tea and juice samples. Combination with seven characterizations of the material confirmed the successful preparation. Effecting the imprinting conditions and extraction efficiency parameters were optimized separately. Selective and competitive adsorption experiments indicated that the materials could specific recognition polyphenols. Using solid phase extraction and high performance liquid chromatography method, the detection limits were 0.005-0.046⯵g mL-1 and the recoveries were between 82.3-104.3%. The improved adsorption performance may be assigned to the synergistic effects among boronate-affinity, hollow SnO2, and 2-AE self-polymerization. It may enhance binding cavities, hydrophilicity, biocompatibility of adsorbent material, and prevent the aggregation of Sn during the preparation processes.
Assuntos
Impressão Molecular/métodos , Polifenóis/análise , Compostos de Estanho/química , Adsorção , Bebidas/análise , Compostos de Boro , Ácidos Cafeicos/análise , Catequina/análise , Ácido Clorogênico/análise , Cromatografia Líquida de Alta Pressão , Limite de Detecção , Polimerização , Polímeros/química , Extração em Fase SólidaRESUMO
BACKGROUND: To observe the impact of application of bio-amniotic membrane immersed in 5-fluorouracil solution in trabeculectomy on the retina in a rabbit model. MATERIALS AND METHODS: Healthy white New Zealand rabbits were randomly assigned into three groups with 20 in each group. Bio-amniotic membranes of 4 × 5 mm immersed in either physiological saline/water for 10 min, or 25 mg/mL 5-fluorouracil solution for 5 and 10 min, respectively, were applied on rabbit eyes during trabeculectomy. At 7, 14, 21, and 28 days of postoperation, five rabbits from each group were examined with electroretinogram (ERG). After being examined for eye pressure and bleb morphology, rabbits were sacrificed by air embolism and their retinas were collected and examined by transmission electron microscopy (TEM). In addition, 5-fluorouracil amount in bio-amniotic membranes was measured using high-performance liquid chromatography. RESULTS: Each bio-amniotic membrane could absorb 59.004 µg and 75.828 µg 5-fluorouracil after being immersed in 5-fluorouracil solution for 5 and 10 min, respectively. Application of these bio-amniotic membranes in trabeculectomy could promote the formation of well-functioning bleb and maintain intraocular pressure, although it had no effect on retina structures as examined with ERG and TEM. CONCLUSION: Application of 5-FU soaked bio-amniotic membrane in rabbit eye trabeculectomy is effective and safe.