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1.
Anal Methods ; 16(22): 3587-3596, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38804081

RESUMO

A magnetic, mesoporous core/shell structured Fe3O4@SiO2@mSiO2 nanocomposite was synthesized and employed as a magnetic solid phase extraction (MSPE) sorbent for the determination of trace sulfonamides (SAs) in food samples. The synthesized nanocomposite was characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, X-ray diffraction, N2 sorption analysis and vibrating sample magnetometry. The results showed that Fe3O4@SiO2@mSiO2 possessed a mesoporous structure with a large surface area. Batch experiments were carried out to investigate the adsorption ability for SAs. Fe3O4@SiO2@mSiO2 showed fast kinetics and high adsorption capacity, and the pseudo-second-order model and Langmuir adsorption isotherm are well fitted with the experimental data, indicating that chemical adsorption might be the rate-limiting step. Moreover, the high adsorption capacity can be maintained for at least 8 runs, indicating excellent stability and reusability. The proposed method exhibited good linearity in the range of 0.2-500 µg L-1, the R2 values of all the analytes were greater than 0.99 and the LODs were all lower than 0.2 µg L-1. Furthermore, real food samples were successfully analyzed with Fe3O4@SiO2@mSiO2 and high recoveries varying from 89.7% and 110.6% were obtained with low relative standard deviations ranging from 1.78% to 6.91%. The Fe3O4@SiO2@mSiO2 magnetic nanocomposite is a promising sorbent for the efficient extraction of SAs from complex food samples.


Assuntos
Nanopartículas de Magnetita , Dióxido de Silício , Extração em Fase Sólida , Sulfonamidas , Sulfonamidas/isolamento & purificação , Sulfonamidas/análise , Sulfonamidas/química , Nanopartículas de Magnetita/química , Adsorção , Dióxido de Silício/química , Extração em Fase Sólida/métodos , Contaminação de Alimentos/análise , Análise de Alimentos/métodos , Porosidade , Nanocompostos/química , Limite de Detecção
2.
Anal Chim Acta ; 1278: 341692, 2023 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-37709445

RESUMO

BACKGROUND: Liver cancer is one of the most common cancers in the world, and it seriously threatens human life and health. Alpha-fetoprotein (AFP), as a carcinogenic glycoprotein, is an important serum marker for detecting liver cancer. Therefore, the accurate and sensitive determination of AFP is crucial for the early diagnosis and treatment of liver cancer. To this end, a label-free fluorescence aptasensor for detecting AFP based on the use of a novel organic Compound D with an aggregation-induced emission activity and aptamer-modified magnetic microparticles was constructed. RESULTS: Compound D could combine with the complementary short chain of the aptamer (CSC-Apt) of AFP to form the D/CSC-Apt complex and realize the fluorescence enhancement of Compound D. Then, magnetic particles modified by the Apt of AFP (Apt-Fe3O4) were prepared. When AFP (or nontarget substance) and D/CSC-Apt were successively added to the Apt-Fe3O4 solution, Apt-Fe3O4 selectively bound to AFP or the D/CSC-Apt complex. Magnetic separation technology showed the changes in the fluorescence intensity of the supernatant. The research results revealed a good linear relationship between the changes in the fluorescence intensity of the supernatant and concentration of AFP within the concentration range of 10-10000 pg mL-1. The proposed aptasensor could achieve high-sensitivity and high-specificity detection of AFP, and its limit of detection was 3 pg mL-1 (S/N = 3). SIGNIFICANCE AND NOVELTY: The sensor combines the advantages of high selectivity of Apt, high sensitivity of fluorescence analysis, AIE effect and good water solubility of Compound D, and rapid separation using magnetic separation technology. And it can be directly used for the detection of AFP in actual serum samples with high accuracy, whereas most of the methods reported in the literature can only detect AFP in spiked serum samples.


Assuntos
Neoplasias Hepáticas , alfa-Fetoproteínas , Humanos , Carcinógenos , Fluorometria , Neoplasias Hepáticas/diagnóstico , Oligonucleotídeos , Compostos Orgânicos
3.
J Fluoresc ; 33(3): 955-963, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36538144

RESUMO

Insulin, the only hormone regulating blood glucose level, is strongly associated with diabetes and its complications. Specific recognition and ultrasensitive detection of insulin are of clinical significance for the early diagnosis and treatment of diabetes. Inspired by aggregation-induced emission, we presented a turn-on label-free fluorescence aptasensor for insulin detection. Quaternized tetraphenylethene salt was synthesized as the fluorescence probe. Guanine-rich aptamer IGA3 was selected as recognition element. Graphene oxide was chosen as the quencher. Under optimized conditions, the fluorescence aptasensor displayed a wide linear range (1.0 pM-1.0 µM) with a low limit of detection (0.42 pM). Furthermore, the aptasensor was successfully applied to detect insulin in human serum. Spiked recoveries were obtained in the range of 96.06%-104.26%. All these results demonstrated that the proposed approach has potential application in the clinical diagnostics of diabetes.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Diabetes Mellitus , Humanos , Insulina , Técnicas Biossensoriais/métodos , Espectrometria de Fluorescência , Diabetes Mellitus/diagnóstico , Limite de Detecção
4.
Spectrochim Acta A Mol Biomol Spectrosc ; 262: 120115, 2021 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-34218179

RESUMO

A rapid and simple fluorescence probe based on CeO2 quantum dots (QDs) was developed for highly selective and ultrasensitive direct determination of 4-nitrophenol (4-NP). CeO2 QDs were prepared using the sol-gelmethod with the precursor of Ce(NO3)3·6H2O as a cerium source. The products were characterized through high-resolution electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy. The fluorescent probe based on CeO2 QDs exhibited a broad linear response to the concentration of 4-NP in the range of 0.005-75.00 µM and provided a low detection limit of 1.50 nM. The fluorescence of CeO2 QDs was quenched by 4-NP through the fluorescence resonance energy transfer mechanism owing to the well overlaps between the fluorescence emission spectrum of CeO2 QDs with the ultraviolet absorption spectrum of 4-NP. This result was confirmed by the time-resolved fluorescence spectra and the evaluation of the interaction distance between CeO2 QDs and 4-NP. The prepared CeO2 QDs are successfully applied to the determination of 4-NP in real water samples, where the spiked recoveries range from 98.2% to 102.4%.


Assuntos
Pontos Quânticos , Transferência Ressonante de Energia de Fluorescência , Corantes Fluorescentes , Nitrofenóis
5.
Drug Des Devel Ther ; 15: 51-60, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33442236

RESUMO

OBJECTIVE: Pre-B cell colony enhancing factor (PBEF) is an important proinflammatory cytokine involved in acute lung injury. However, whether PBEF participates in lung injury caused by cardiopulmonary bypass (CPB) is still unknown. This study aimed to investigate the effects of silencing PBEF on lung injury and the sodium and water transport system in rats receiving CPB. METHODS: Morphological changes in lung tissues were evaluated using hematoxylin and eosin (H&E) staining. PBEF was detected using immunohistochemistry. The sodium and water transport system-related proteins and cellular signaling pathways were detected by Western blotting. RESULTS: Rats receiving CPB (model group) had more severe alveolar wall damage and higher expression of PBEF in free form than the control rats. Western blotting showed that the expression of PBEF, surfactant protein D (SP), aquaporin (AQP) 1, AQP5, and epithelial sodium channel (ENaC) was significantly higher in the lung tissue of CPB rats than control rats. By contrast, adenovirus-encoding sh-PBEF significantly reduced the expression of PBEF, SP, AQP1, AQP5, and ENaC in the lung tissues of rats treated with CPB. The phosphorylation levels of extracellular signal-regulated protein kinases 1 and 2 (ERK1/2), protein kinase B (AKT), and p38 mitogen-activated protein kinase (MAPK) were significantly increased in the lung tissue of rats that received CPB, and were downregulated by adenovirus-encoding sh-PBEF. CONCLUSION: Adenovirus-encoding sh-PBEF could reduce lung injury and repair the sodium-water transport system in rats receiving CPB, likely through reducing MAPK, ERK1/2, and Akt signaling pathways.


Assuntos
Ponte Cardiopulmonar , Pulmão/metabolismo , Nicotinamida Fosforribosiltransferase/metabolismo , Animais , Pulmão/patologia , Masculino , Ratos , Ratos Sprague-Dawley
6.
Cancer Manag Res ; 12: 13043-13049, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33376398

RESUMO

BACKGROUND: No study has reported the risk factors associated with the prognosis of patients with transverse colon cancer. Therefore, we aimed to demonstrate the long-term outcomes of transverse colon cancer patients undergoing radical surgery and explore the prognostic factors. MATERIALS AND METHODS: The clinical data of a total of 366 patients with transverse colon cancer staged from I to IIIC undergoing radical surgery from February 1992 to May 2017 were retrospectively analyzed. Clinicopathological features were recorded, and univariate and multivariate analyses were conducted to evaluate the association between the factors and overall survival (OS) as well as disease-free survival (DFS). Kaplan-Meier curves were generated to assess the association between TNM stage and OS and DFS, respectively. RESULTS: The median follow-up time was 62 months, and the 5-year OS and DFS rates were 87.5% and 86.5%, respectively. In addition, a significant difference was also found in the OS and DFS curves according to TNM stage. The N classification, vascular invasion, differentiation, preoperative CA199, preoperative CA125 and preoperative AFP were significantly associated with OS according to univariate analysis, while N classification and differentiation were independent prognostic factors for OS according to multivariate analysis (both P < 0.05). Similarly, N classification, vascular invasion, differentiation, preoperative CA199, preoperative CA125, and preoperative AFP were statistically correlated with DFS according to univariate analysis, while N classification and preoperative CA199 were independent prognostic factors for DFS according to multivariate analysis (both P < 0.05). CONCLUSION: N classification was an independent factor for both OS and DFS, while differentiation and CA199 were independent prognostic factors only for OS and DFS, respectively.

7.
Minerva Chir ; 75(3): 193-202, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32550728

RESUMO

INTRODUCTION: Thyroid surgery, which is usually followed by moderate postoperative pain, has gained increasing attention in recent years. A systematic review and meta-analysis was conducted to assess the effect of prophylactic bupivacaine on postoperative pain following thyroidectomy. EVIDENCE ACQUISITION: We searched the PubMed, Web of Science, Embase, and Cochrane Library databases for specific keywords. RevMan 5.0 and Stata 12.0 software were used to perform meta-analyses. The endpoints were postoperative pain, rescue analgesic requirement, and postoperative nausea and vomiting (PONV) during the immediate 24 h postoperative period. EVIDENCE SYNTHESIS: A total of 18 randomized controlled trials (RCTs) with 1308 patients were included in the meta-analysis. A significant reduction of pain according to the postoperative pain scale at 1 hour (P<0.05) and rescue analgesic requirement (P<0.05) was observed following local infiltration with bupivacaine. A bilateral superficial cervical plexus block (BSCPB) with bupivacaine also significantly reduced postoperative pain at 1 hour (P<0.01) and 24 hours (P<0.01), as well as rescue analgesic requirement (P<0.00001) and PONV (P<0.01). Compared with BSCPB, local infiltration with bupivacaine provides a better effect in terms of postoperative analgesia (P<0.05). CONCLUSIONS: We recommend local infiltration with bupivacaine ranged from 20 to 75 mg before or after skin closure or BSCPB with bupivacaine ranged from 25 to 100 mg to reduce postoperative pain after thyroidectomy.


Assuntos
Anestésicos Locais/administração & dosagem , Bupivacaína/administração & dosagem , Dor Pós-Operatória/prevenção & controle , Tireoidectomia/efeitos adversos , Analgésicos/uso terapêutico , Bloqueio do Plexo Cervical/métodos , Humanos , Náusea e Vômito Pós-Operatórios , Ensaios Clínicos Controlados Aleatórios como Assunto/estatística & dados numéricos , Terapia de Salvação , Fatores de Tempo
8.
J Cardiothorac Surg ; 15(1): 117, 2020 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-32460862

RESUMO

OBJECTIVES: A polyglycolic acid (PGA) patch is often used in pulmonary bullae resection, but consensus has not been reached on its effect on patient recovery. The aim of the study is to conduct a systematic review and meta-analysis of studies of polyglycolic acid for bullectomy. METHODS: A comprehensive literature search was performed using ScienceDirect, EMBASE, Ovid MEDLINE, PubMed, The Cochrane Library, Scopus, and Google Scholar. Clinical trials that compared PGA versus non-PGA for bullectomy were selected. The clinical endpoints included postoperative recurrence, average postoperative air leakage, prolonged air leaks, drainage tube removal time, and postoperative hospital stay. RESULTS: A total of eight articles (1095 patients) were included. Compared to the non-PGA approach, the PGA approach was associated with lower rates of postoperative recurrence (95% confidence interval [CI]: 0.16 to 0.39, p < 0.00001),) and of prolonged air leaks (95% CI: 0.29 to 0.72, p = 0.0007); a shorter time of drainage tube removal (95% CI: - 1.36 to - 0.13, p = 0.02); The time of average postoperative air leakage, postoperative hospital stay and operative time did not show a significant difference between the two groups. CONCLUSIONS: These results suggest that the use of PGA patch might can prevent the postoperative recurrence of spontaneous pneumothorax and decrease the rates of prolonged air leaks. More large-scale, high-quality randomized controlled trials are required to confirm our finding.


Assuntos
Pneumotórax/terapia , Ácido Poliglicólico/administração & dosagem , Implantes Absorvíveis , Vesícula/terapia , Humanos , Pleurodese/instrumentação , Complicações Pós-Operatórias , Recidiva
9.
ACS Sens ; 5(5): 1445-1454, 2020 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-32295340

RESUMO

A novel SiO2@ MIPIL fluorescence sensor for the highly sensitive detection of 2,4,6-trichlorophenol was prepared by using surface molecularly imprinting technology with SiO2 microspheres as carriers and 3,3'-(anthracene-9,10-diylbis(methylene))bis(1-vinyl-1H-imidazole-3-ium) chloride as a double recognition fluorescence functional monomer. The prepared molecularly imprinted polymer (SiO2@MIPIL) was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, laser confocal microscopy, and nuclear magnetic resonance. Compared with the polymer obtained via bulk polymerization (MIPIL), the surface molecularly imprinted polymer (SiO2@MIPIL) has a better linear range (0.1-50 nM), lower detection limit (89 pM), and shorter detection time (approximately 1.5 min). The fluorescence sensor also shows good specificity, high sensitivity, good stability, and reusability. Satisfactory results were obtained when using this sensor in industrial wastewater and spiked environmental water.


Assuntos
Clorofenóis , Impressão Molecular , Polímeros , Dióxido de Silício
10.
Spectrochim Acta A Mol Biomol Spectrosc ; 228: 117714, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-31718976

RESUMO

A novel fluorescent biosensor based on dabcyl [(E)-4-((4-(dimethylamino) phenyl) diazenyl)benzoic acid] -modified anti-Mb aptamer (D-AMA) and 6-FAM(6-carboxyfluorescein) -modified complementary short chain (F-CSC)for the specific and sensitive detection of Mb levels is presented in this study. In PBS buffer solution, D-AMA bound to F-CSC, and then dabcyl quenched the fluorescence of 6-FAM. After adding Mb into the system, D-AMA bound to Mb and separated from F-CSC. The fluorescence of 6-FAM was restored after it separated from dabcyl. The assay exhibited high specificity and sensitivity toward Mb, with a low limit of detection of 0.07 ng/mL (S/N = 3) and linear relationships of 0.1-5 ng/mL. It was further applied to detect Mb levels in spiked human blood sera samples.


Assuntos
Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais , Fluoresceínas/química , Mioglobina/sangue , Animais , Sequência de Bases , Bovinos , DNA/análise , Humanos , Espectrometria de Fluorescência
11.
Dalton Trans ; 48(42): 15970-15976, 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31595278

RESUMO

The potential of metal ß-diketonate complexes for the catalysis of the chemical fixation of CO2 into cyclic carbonates at 1 atm CO2 and near room temperature was demonstrated. Their potential for the capture and simultaneous conversion of CO2 in a dilute CO2 stream was also determined. The catalysts were easily synthesized and commercially available. Therefore, this CO2 transformation was less energy- and material-consuming, which made this reaction closer to true "green" chemistry.

12.
Cancer Biol Ther ; 20(11): 1380-1388, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31387444

RESUMO

Background The prognostic value of Chemokine (C-X-C motif) ligand 1 (CXCL1) in various types of cancer remains controversial. Here we aimed to evaluate the prognostic role of CXCL1 for cancer. Methods A comprehensively search of the PubMed, Embase, Web of Science, Wanfang and China National Knowledge Internet databases was conducted to retrieve eligible studies meeting the inclusion criteria. Overall survival (OS), progression-free survival (PFS) and various clinicopathological parameters were defined as endpoints. Stata SE12.0 software was used for quantitative meta-analysis. Results A total of 17 studies encompassing 2265 cancer patients were included. Our meta-analysis showed that patients with higher CXCL1 expression had significantly shorter OS, according to both multivariate (HR 1.51, 95% CI 1.19-1.83, P < .01) and univariate analysis (HR 2.08, 95% CI 1.62-2.54, P < .01). Furthermore, higher CXCL1 expression was significantly correlated with advanced TNM stage and lymph node metastasis (both P < .05). Conclusions High CXCL1 expression is a risk factor for cancer prognosis indicating a poor OS, and advanced TNM stage and lymph node metastasis, demonstrating that it may be a promising prognostic biomarker for different cancers.


Assuntos
Biomarcadores Tumorais/genética , Quimiocina CXCL1/genética , Metástase Linfática/genética , Neoplasias/genética , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Metástase Linfática/patologia , Neoplasias/patologia , Intervalo Livre de Progressão , Fatores de Risco
13.
Chem Sci ; 10(19): 5025-5030, 2019 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-31183052

RESUMO

The rational modulation of receptor affinity through distal-site mutation and allosteric control is valuable in biosensor designing to tune the useful dynamic range. Our ability to programmatically engineer dual-affinity regulation into diverse affinities of target binding and activities of hybridization chain reaction, however, remains limited. By programmable engineering of the switching equilibria of the recognition hairpin using distal-site mutation inhibition and allosteric activation, we obtained a set of receptors varying significantly in affinities of target binding and activities of the hybridization chain reaction. For the first time, we developed an electrocatalytic biosensor for nucleic acid detection with a tunable dynamic range based on a conformational switch triggered bidirectional hybridization chain reaction and blocker assisted multivalent binding. This designable biosensor thus enables single-step incubation, diverse affinities of target binding, diverse efficiencies of signal amplification and diverse single nucleotide discrimination for quantitative analyses of nucleic acids of various lengths in serum, which holds great potential as a compelling platform suitable for liquid biopsy.

14.
Mikrochim Acta ; 186(5): 287, 2019 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-30989406

RESUMO

The authors describe a fluorometric assay for cardiac myoglobin (Mb), a marker for myocardial infarction. An Mb-binding aptamer was labeled with pyrene and adsorbed on the surface of graphene oxide (GO) via noncovalent and reversible binding forces. This causes the fluorescence of pyrene (best measured at excitation/emission wavelengths of 275/376 nm) to be quenched. However, fluorescence is restored on addition of pyrene due to the strong affinity between Mb and aptamer which causes its separation from GO. Fluorescence increases linearly in the 5.6-450 pM Mb concentration range, and the lower detection limit is 3.9 pM (S/N = 3). The assay was applied to the determination of cardiac Mb in spiked serum, and satisfactory results were obtained. Graphical abstract Schematic presentation of the detection of Mb (cardiac myoglobin) by using a fluorometric method based on pyrene-modified anti-Mb aptamer and GO (graphene oxide) through fluorescence quenching and subsequent recovery.


Assuntos
Aptâmeros de Nucleotídeos/metabolismo , Técnicas Biossensoriais/métodos , Grafite/química , Miocárdio/metabolismo , Mioglobina/análise , Pirenos/química , Transferência de Energia , Fluorometria , Humanos , Limite de Detecção , Mioglobina/metabolismo
15.
Nanomaterials (Basel) ; 9(3)2019 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-30832300

RESUMO

A novel, facile sensor was further developed for microcystin-LR (MC-LR) determination by visible spectroscopy. Antibody-functionalized SiO2-coated magnetic nanoparticles (Fe3O4@SiO2) and aptamer-functionalized polydopamine nanospheres decorated with Cu nanoparticles (PDA/CuNPs) recognized specific sites in MC-LR and then the sandwich-type composites were separated magnetically. The Cu in the separated composites was converted to Cu2+ ions in solution and turn-on visible absorption was achieved after reaction with bis(cyclohexanone)oxaldihydrazone (BCO) (λmax = 600 nm). There was a quantitative relationship between the spectral intensity and MC-LR concentration. In addition, under the optimum conditions, the sensor turns out to be a linear relationship from 0.05 to 25 nM, with a limit of detection of 0.05 nM (0.05 µg/L) (S/N = 3) for MC-LR. The sensitivity was dependent on the low background absorption from the off-to-on spectrum and label amplification by the polydopamine (PDA) surface. The sensor had high selectivity, which shows the importance of dual-site recognition by the aptamer and antibody and the highly specific color formed by BCO with Cu2+. The bioassay was complete within 150 min, which enabled quick determination. The sensor was successfully used with real spiked samples. These results suggest it has potential applications in visible detection and could be used to detect other microcystin analogs.

16.
Nanomaterials (Basel) ; 9(2)2019 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-30736333

RESUMO

The nanocomposite preparation procedure plays an important role in achieving a well-established heterostructured junction, and hence, an optimized photocatalytic activity. In this study, a series of g-C3N4/ZnO nanocomposites were prepared through two distinct procedures of a low-cost, environmentally-friendly, in-situ fabrication process, with urea and zinc acetate being the only precursor materials. The physicochemical properties of synthesized g-C3N4/ZnO composites were mainly characterized by XRD, UV⁻VIS diffuse reflectance spectroscopy (DRS), N2 adsorption-desorption, FTIR, TEM, and SEM. These nanocomposites' photocatalytic properties were evaluated in methylene blue (MB) dye photodecomposition under UV and sunlight irradiation. Interestingly, compared with ZnO nanorods, g-C3N4/ZnO nanocomposites (x:1, obtained from urea and ZnO nanorods) exhibited weak photocatalytic activity likely due to a "shading effect", while nanocomposites (x:1 CN, made from g-C3N4 and zinc acetate) showed enhanced photocatalytic activity that can be ascribed to the effective establishment of heterojunctions. A kinetics study showed that a maximum reaction rate constant of 0.1862 min-1 can be achieved under solar light illumination, which is three times higher than that of bare ZnO nanorods. The photocatalytic mechanism was revealed by determining reactive species through adding a series of scavengers. It suggested that reactive ∙O2- and h⁺ radicals played a major role in promoting dye photodegradation.

17.
Analyst ; 143(23): 5849-5856, 2018 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-30382260

RESUMO

In this study, lysozyme-based magnetic molecularly imprinted polymers (Lyz-MMIPs) for selective recognition and magnetic separation of lysozyme in human urine were prepared via surface imprinting technology. The morphology and structural properties of the resultant Lyz-MMIPs were characterized by using transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), thermogravimetry (TG), X-ray diffraction (XRD) and a vibrating sample magnetometer (VSM). The results showed that the Lyz-MMIPs exhibited a uniform core-shell structure and favorable magnetic properties with a saturation magnetization of 14.8 emu g-1. To obtain the best selectivity and binding performance, the pH value of adsorption solution was investigated in detail. Under the optimized conditions, the Lyz-MMIPs possessed high binding and specific recognition capacity, as well as fast binding kinetics and phase separation rates. Moreover, the saturation binding capacity of Lyz-MMIPs reached 124.3 mg g-1, which was nearly 3.2 times that of lysozyme-based magnetic non-imprinted polymers (Lyz-MNIPs). In addition, the selectivity and reusability experiments showed that the Lyz-MMIPs displayed significant selectivity and favorable reusability. Furthermore, the Lyz-MMIPs were successfully applied for the determination and separation of lysozyme in human urine with satisfactory recovery rates. Above all, the synthetic process was quite simple and this strategy may provide a versatile approach for the fabrication of well-defined molecularly imprinted polymers on magnetic nanoparticles for the analysis of complicated matrixes.


Assuntos
Nanopartículas de Magnetita/química , Muramidase/urina , Polímeros/química , Humanos , Concentração de Íons de Hidrogênio , Cinética , Fenômenos Magnéticos , Impressão Molecular/métodos
18.
Chem Soc Rev ; 47(16): 6101-6127, 2018 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-30022215

RESUMO

As a two-dimensional (2D) material, molybdenum disulfide (MoS2) exhibits unique electronic and optical properties useful for a variety of optoelectronic applications including light harvesting. In this article, we review recent progress in the synthesis, properties and applications of MoS2 and related heterostructures. Heterostructured materials are developed to add more functionality or flexibility compared to single component materials. Our focus is on their novel properties and functionalities as well as emerging applications, especially in the areas of light energy harvesting or conversion. We highlight the correlation between structural properties and other properties including electronic, optical, and dynamic. Whenever appropriate, we also try to provide fundamental insight gained from experimental as well as theoretical studies. Finally, we discuss some current challenges and opportunities in technological applications of MoS2.

19.
Biosens Bioelectron ; 108: 38-45, 2018 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-29499557

RESUMO

Molecularly imprinted polymers prepared using traditional functional monomers and cross-linkers exhibit slow binding kinetics, low electrocatalytic activity and adsorption capacity. Herein, we report a new composite of ionic liquid-based graphene and molecularly imprinted polymer (IL-GR-MIP) with high electrocatalytic activity and adsorption capacity to construct an effective electrochemical sensor for 6-benzylaminopurine (6-BAP). Our objective was to enhance the efficiency of the sensor by incorporating more IL in the MIP framework. We synthesized IL-GR-MIP using ionic liquid 1-vinyl-3-butylimidazolium tetrafluoroborate (IL1) as functional monomer, ionic liquid 1,4-butanediyl-3,3'-bis-l-vinylimidazolium dibromide (IL2) as cross-linker, 6-BAP as template, and GR as supporter. IL-GR-MIP was characterized by Fourier transform infrared spectroscopy, thermal gravimetric analysis, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscope. Compared with GR-MIP composites based on methacrylic acid or IL1 as functional monomer, N, N'-methylenebisacrylamide and ethylene glycol dimethacrylate as cross-linker, the IL-GR-MIP (prepared with ionic liquids as functional monomer and cross-linker) sensor exhibited highest peak current for 6-BAP. The results indicate the ability of IL2 as cross-linker to enhance electrocatalytic activity and adsorption capacity for 6-BAP of IL-GR-MIP. Under the optimized conditions, the peak current of IL-GR-MIP sensor was linear to 6-BAP concentration in the range of 0.5-50 µM with a detection limit of 0.2 µM (S/N = 3). The IL-GR-MIP sensor exhibited good selectivity with the anti-interference ability of 1000-fold ascorbic acid in 6-BAP determination. Furthermore, we demonstrated practical applicability of IL-GR-MIP sensor in detecting 6-BAP in real samples with satisfactory results.


Assuntos
Compostos de Benzil/análise , Técnicas Biossensoriais/métodos , Citocininas/análise , Técnicas Eletroquímicas/métodos , Impressão Molecular/métodos , Reguladores de Crescimento de Plantas/análise , Polímeros/química , Purinas/análise , Acrilamidas/química , Adsorção , Compostos de Benzil/química , Catálise , Citocininas/química , Grafite/química , Imidazóis/química , Líquidos Iônicos/química , Limite de Detecção , Metacrilatos/química , Reguladores de Crescimento de Plantas/química , Polímeros/síntese química , Purinas/química
20.
J Sep Sci ; 41(11): 2479-2487, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29466619

RESUMO

We developed a facile approach to the construction of bio-recognition sites in silica nanoparticles for efficient separation of bovine hemoglobin based on amino-functionalized silica nanoparticles grafting by 3-aminopropyltriethoxylsilane providing hydrogen bonds with bovine hemoglobin through surface molecularly imprinting technology. The resulting amino-functionalized silica surface molecularly imprinted polymers were characterized using scanning electron microscope, transmission electronic microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. Results showed that the as-synthesized imprinted polymers exhibited spherical morphology and favorable thermal stability. The binding adsorption experiments showed that the imprinted polymers can reach equilibrium within 1 h. The Langmuir isotherm and pseudo-second-order kinetic model fitted the adsorption data well. Meanwhile, the imprinted polymers possessed a maximum binding capacity up to 90.3 mg/g and highly selectivity for the recognition of bovine hemoglobin. Moreover, such high binding capacity and selectivity retained after eight cycles, indicating the good stability and reusability of the imprinted polymers. Finally, successful application in the selective recognition of bovine hemoglobin from a real bovine blood sample indicated that the imprinted polymers displayed great potentials in efficient purification and separation of target proteins.


Assuntos
Hemoglobinas/isolamento & purificação , Polímeros/química , Extração em Fase Sólida/métodos , Adsorção , Animais , Análise Química do Sangue , Bovinos , Hemoglobinas/química , Ligação de Hidrogênio , Cinética , Impressão Molecular , Polímeros/síntese química , Dióxido de Silício/química , Extração em Fase Sólida/instrumentação , Espectroscopia de Infravermelho com Transformada de Fourier
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