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1.
Food Funct ; 2024 Aug 08.
Article in English | MEDLINE | ID: mdl-39115429

ABSTRACT

The incidence of hyperuricemia (HUA) shows a gradually increasing trend towards affecting younger individuals, and it can significantly harm the overall health status of the body. Based on a metabolomics perspective, this study reveals the mechanism of the uric acid-lowering action of Prunus salicina Lindl. cv. "furong" polyphenols (PSLP) on a hyperuricemia mouse model induced by hypoxanthine and potassium oxybutyrate. The results demonstrate that PSLP comprise an effective treatment strategy for reducing the levels of serum uric acid (SUA), serum creatinine (SCr) and blood urea nitrogen (BUN) in HUA mice (p < 0.05), wherein the maximum decrease rates are up to 44.50%, 29.46%, and 32.95%, respectively. PSLP are observed to exert a pronounced inhibitory effect on the activities of xanthine oxidase (XOD) and adenosine deaminase (ADA) in the livers of HUA mice, with reductions of up to 16.36% and 20.13%, respectively. These findings illustrate that PSLP exert a significant uric acid-lowering effect. Subsequent metabolomic analysis of mouse serum identified 28 potential biomarkers for hyperuricemia, whose levels were markedly diminished by PSLP. This process involved alterations in purine, glycine, the pentose phosphate pathway, and galactose metabolism. Twenty-eight potential biomarkers were identified for hyperuricemia by subsequent metabolomic analysis of mouse serum, whose levels were markedly reversed by PSLP intervention. The regulation of HUA by PSLP involved alterations in purine metabolism, glycerolipid metabolism, the pentose phosphate pathway, and galactose metabolism. The mechanism of PSLP ameliorated hyperuricemia might be attributed to reduction of the level of the uric acid precursor ribose-5-phosphate in the pentose phosphate pathway, the inhibition of the activities of uric acid synthase XOD and ADA in purine metabolism, and reduction of the synthesis of the end product uric acid. This study provides a theoretical basis for the development of functional foods based on PSLP, which can potentially reduce uric acid levels.

2.
Food Chem ; 440: 138185, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38100966

ABSTRACT

A sensitive electrochemical assay for simultaneously detecting cadmium ion (Cd2+) and mercury ion (Hg2+) with the aptamer as recognition unit was established, in which methylene blue (MB) and target-triggered in-situ generated Ag nanoclusters (Ag NCs) were identified as signal reporters. Multi-walled carbon nanotubes and gold nanoparticles composites were prepared with polyethyleneimine to amplify electrical signals of screen-printed electrodes. Due to the particular base sequences, MB labeled Cd2+ aptamer paired with ssDNA through T-Hg-T structure with Hg2+. Notably, the C-rich structure in ssDNA acted as a template for the generation of Ag NCs, which could induce differential pulse voltammetry signals corresponding to Hg2+ concentrations. This electrochemical aptasensor exhibited detection limits of 94.01 pg/mL and 15.74 pg/mL for Cd2+ and Hg2+, respectively. The developed aptasensor allowed for practical application to tea and vegetable samples with satisfactory accuracy. This work possesses potential in developing biosensing technologies for simultaneous determination of multiple heavy metals.


Subject(s)
Aptamers, Nucleotide , Biosensing Techniques , Mercury , Metal Nanoparticles , Nanotubes, Carbon , Gold/chemistry , Cadmium , Nanotubes, Carbon/chemistry , Methylene Blue/chemistry , DNA, Single-Stranded , Electrodes , Electrochemical Techniques , Aptamers, Nucleotide/chemistry , Limit of Detection
3.
Foods ; 12(24)2023 Dec 07.
Article in English | MEDLINE | ID: mdl-38137202

ABSTRACT

The structural characteristics and anti-inflammatory activity of Tremella fuciformis polysaccharides (TFPs) were investigated. The study showed that TFPs were mainly composed of mannose, rhamnose, glucuronic acid, glucose, galactose, xylose, and fucose. TFPs significantly inhibited monosodium urate (MSU)-induced inflammation of RAW264.7 cells, as well as the secretion levels of TNF-α, IL-1ß, and IL-18 cytokines. The concentrations of malondialdehyde and reactive oxygen species in RAW264.7 macrophages were reduced, but superoxide dismutase activity was increased. RNA-Seq technology was applied to explore the mechanisms of TFPs ameliorating MSU-induced inflammation of RAW264.7 macrophages. Results revealed that TFPs significantly reduce MSU-stimulated inflammatory damage in RAW 264.7 cells by inhibiting signaling pathways like the hypoxia inducible factor-1 (HIF-1) signaling pathway and erythroblastic oncogene B (ErbB) signaling pathway. This study provides a foundation for TFPs to be developed as novel anti-inflammatory drugs.

4.
Biosensors (Basel) ; 13(8)2023 Jul 28.
Article in English | MEDLINE | ID: mdl-37622852

ABSTRACT

In order to improve the detection performance of surface-enhanced Raman scattering (SERS), a low-cost Au@Ag nanorods (Au@Ag NRs) substrate with a good SERS enhancement effect was developed and applied to the detection of malachite green (MG) in aquaculture water and crayfish. By comparing the SERS signal enhancement effect of five kinds of Au@Ag NRs substrates with different silver layer thickness on 4-mercaptobenzoic acid (4-MBA) solution, it was found that the substrate prepared with 100 µL AgNO3 had the smallest aspect ratio (3.27) and the thickest Ag layer (4.1 nm). However, it showed a good signal enhancement effect, and achieved a detection of 4-MBA as low as 1 × 10-11 M, which was 8.7 times higher than that of the AuNRs substrate. In addition, the Au@Ag NRs substrate developed in this study was used for SRES detection of MG in crayfish; its detection limit was 1.58 × 10-9 M. The developed Au@Ag NRs sensor had the advantages of stable SERS signal, uniform size and low cost, which provided a new tool for SERS signal enhancement and highly sensitive SERS detection method development.


Subject(s)
Nanotubes , Rosaniline Dyes , Aquaculture
5.
Nanotechnology ; 34(49)2023 Sep 27.
Article in English | MEDLINE | ID: mdl-37604147

ABSTRACT

It is of great significance for electrochemical sensors to simultaneously detect dopamine (DA) and uric acid (UA) related to biological metabolism. In this work, two-dimensional (2D) porous carbon nanosheets (CNS) was prepared as electrocatalysts to improve the sensitivity, the selectivity, and the detection limit of the simultaneous detection. First, 2D amorphous iron-metal organic frameworks (Fe-MOF) was synthesized with Fe3+and terephthalic acid via a facile wet chemistry method at room temperature. And then, CNS was prepared by pyrolysis and pickling of Fe-MOF. CNS had large specific surface area, good electrical conductivity and lots of carbon defects. The response currents of the CNS modified electrode was larger than those of the control electrodes in the simultaneous determination. The simultaneous determination was measured via differential pulse voltammetry to reduce the effect of capacitive currents on quantitative analysis. The CNS modified electrodes showed high sensitivity and low detection limit for the simultaneous detection of DA and UA. The modified electrodes have been successfully used to detect DA and UA in normal human serum.


Subject(s)
Carbon , Dopamine , Humans , Dopamine/analysis , Uric Acid/analysis , Porosity , Ascorbic Acid/analysis , Electrodes , Electrochemical Techniques/methods
6.
J Agric Food Chem ; 71(29): 11195-11203, 2023 Jul 26.
Article in English | MEDLINE | ID: mdl-37439107

ABSTRACT

The detection of heavy metals in food is beneficial to public health. Herein, a new time-resolved fluorescent immunosensor based on the Förster resonance energy transfer (FRET) was proposed to rapidly detect a cadmium ion (Cd2+). After coupling with an antigen and a monoclonal antibody (mAb), respectively, the synthesized europium (III)-chelate-doped polystyrene time-resolved fluorescence microsphere-antigen (Eu-antigen) and gold nanoflowers-mAb (GNFs-mAb) interacted by antigen-antibody combination to quench fluorescence through FRET. Under optimal conditions, the Eu-GNF immunosensing platform provided a quick response to Cd2+ within 30 min. The limit of detection was 0.29 ng/mL with a linear range of 1-500 ng/mL. This immunosensor was further validated via graphite furnace atomic absorption spectrometry and exhibited satisfactory recovery for the detection of Cd2+ in four kinds of tea samples (98.82-108.01%). Thus, this strategy provides a good paradigm for the rapid and high-throughput detection of heavy metals in field testing.


Subject(s)
Biosensing Techniques , Graphite , Metal Nanoparticles , Fluorescence Resonance Energy Transfer/methods , Cadmium , Biosensing Techniques/methods , Immunoassay/methods , Europium/chemistry , Gold/chemistry , Antibodies, Monoclonal , Limit of Detection , Metal Nanoparticles/chemistry
7.
Foods ; 12(8)2023 Apr 17.
Article in English | MEDLINE | ID: mdl-37107464

ABSTRACT

Blanching is a critical step in the processing of Tremella fuciformis (T. fuciformis). The effects of different blanching methods (boiling water blanching (BWB), ultrasonic-low temperature blanching (ULTB), and high-temperature steam (HTS)) on the quality and moisture migration characteristics of T. fuciformis were investigated. The results showed that the T. fuciformis blanched by ULTB (70 °C, 2 min, 40 kHz, 300 W) had the best quality, including a brighter appearance, superior texture, and good sensory features, with a polysaccharide content of 3.90 ± 0.02%. The moisture migration characteristics of T. fuciformis after blanching exhibited four peaks, displayed strong and weak chemically bound water, immobilized water, and free water, whereas ULTB had a weak effect on the freedom of water in T. fuciformis. The study will provide the foundation for the factory processing of T. fuciformis.

8.
Foods ; 12(2)2023 Jan 05.
Article in English | MEDLINE | ID: mdl-36673346

ABSTRACT

Acute gouty arthritis is an acute inflammatory reaction caused by the deposition of monosodium urate (MSU) crystals in joints and surrounding soft tissues. Controlling inflammation is the key to preventing acute gouty arthritis. Anti-inflammatory activities and the possible molecular mechanisms of plum (Prunus salicina Lindl cv. "furong") polyphenols (PSLP) on RAW264.7 macrophage cells induced by monosodium urate were investigated. PPSF significantly inhibited the activity of inflammatory factors such as tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-18 (IL-18). In addition, PPSF exhibited excellent activation of superoxide dismutase (SOD) activity and reduction of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) levels in RAW264.7 macrophages. The results of global screening of all transcripts by RNA-seq revealed 8585 differentially expressed genes between the PSLP-treated group and the MUS group. From GO analysis, PSLP could affect the occurrence and development of RAW264.7 macrophage inflammation through biological processes, such as organic substance metabolism, intracellular organelles, and binding function. The regulation mechanism of PSLP on MSU-induced RAW264.7 macrophage inflammation may be achieved through the HIF-1 signaling pathway, renal cell carcinoma, the ErbB signaling pathway, and the FoxO signaling pathway. Therefore, PSLP has great prospects in the prevention of gout and similar inflammatory diseases.

9.
Anal Methods ; 13(48): 5830-5837, 2021 12 16.
Article in English | MEDLINE | ID: mdl-34842866

ABSTRACT

The presence of Cd2+, Pb2+, Cu2+ and Hg2+ in drinking-water can be harmful to human health, even if their concentration is fairly low. Hence, it is significant to detect these heavy metal ions in sewage to evaluate the quality of water. Herein, amino-functionalized metal-organic frameworks (NH2-MIL-88(Fe)) embedded with graphitic carbon nitride (g-C3N4) nanosheets and acid-functionalized carbon nanotubes were prepared via a one-pot synthesis. The composite can be directly modified on the surface of glass carbon electrodes without the assistance of Nafion or other binders. The modified glass carbon electrodes can be used to simultaneously detect Cd2+, Pb2+, Cu2+ and Hg2+ in water via square wave stripping voltammetry. The doping of g-C3N4 in the composite, rich in N-containing functional groups, participates in the adsorption of metal ions on the surface of the electrodes. The porous composite provides accommodation room for metals generated by electro-reduction. The detection limit for Cd2+, Pb2+, Cu2+ and Hg2+ is 39.6 nM, 7.6 nM, 11.9 nM, and 9.6 nM, respectively. And the sensitivity for Cd2+, Pb2+, Cu2+ and Hg2+ is 0.0789 mA µM-1 cm-2, 0.4122 mA µM-1 cm-2, 0.2616 mA µM-1 cm-2, and 0.3251 mA µM-1 cm-2, respectively. This work not only enriches the functional design of Fe-MOF materials, but also develops a method for the determination of metal ions using the adsorption sites in g-C3N4.


Subject(s)
Drinking Water , Metals, Heavy , Nanocomposites , Nanotubes, Carbon , Humans , Ions , Metals, Heavy/analysis
10.
J Dermatol ; 48(12): 1900-1906, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34580903

ABSTRACT

Pseudomyogenic hemangioendothelioma (PHE) is an extremely rare disease that affects mainly the young and more men than women. PHE are multicentric, locally aggressive, have low metastatic potential, and affect multiple tissue planes. Genetic aberrations are frequently detected in PHE and may play important roles in the occurrence, development, and treatment of this disease. In this study, we report a case of PHE with a novel SERPINE1-FOSB fusion gene. The fusion introduced a strong promoter near the coding region of FOSB, resulting in overexpression of intact FOSB. Immunohistochemical analysis showed overexpression of pAKT and mTOR in tumor cells, suggesting activation of the PI3K-AKT-mTOR signaling pathway. The patient responded well to targeted therapy with sirolimus, an mTOR inhibitor. Our study correlated dysregulation of a specific signaling pathway and the effectiveness of a targeted therapy to a specific genetic aberration. This information may be useful for future investigations of targeted therapeutics and provide a potential predictive biomarker for therapeutic effectiveness in PHE cases.


Subject(s)
Hemangioendothelioma , Phosphatidylinositol 3-Kinases , Female , Hemangioendothelioma/drug therapy , Hemangioendothelioma/genetics , Humans , Male , Phosphatidylinositol 3-Kinases/genetics , Plasminogen Activator Inhibitor 1 , Proto-Oncogene Proteins c-akt/genetics , Proto-Oncogene Proteins c-fos/genetics , Proto-Oncogene Proteins c-fos/metabolism , Signal Transduction/genetics , Sirolimus/therapeutic use , TOR Serine-Threonine Kinases/genetics
11.
Nanoscale Res Lett ; 14(1): 71, 2019 Feb 28.
Article in English | MEDLINE | ID: mdl-30820698

ABSTRACT

How to fabricate scale low-cost microfluidic device for detection of biomarkers owns a great requirement. Herein, it is for the first time reported that a new microfluidic device based on bonding polydimethylsiloxane microfluidic channels onto the substrate of a screen-printed electrode with coating glass solution was fabricated for electrochemical sensing of prostate-specific antigen (PSA). Compared to traditional microfabrication processes, this method is simple, fast, low cost, and also suitable for mass production. The prepared screen-printed electrode-based microfluidic device (CASPE-MFD) was used for the detection of the PSA in human serum. The prepared CASPE-MFD had a detection limit of 0.84 pg/mL (25.8 fM) and a good linearity with PSA concentration ranging from 0.001 to 10 ng/mL, which showed a great promise platform toward the development of miniaturized, low-cost electrochemical microfluidic device for use in human health, environmental monitoring, and other applications.

12.
Environ Pollut ; 247: 9-17, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30648618

ABSTRACT

Release of phosphorus (P) from sediment to overlying water has to be dealt with to address algal blooms in eutrophic lakes. In this study, the sediment from the Lake Taihu was amended with lanthanum modified zeolite (LMZ) to reduce P release under different pH, temperature and anaerobic conditions. LMZ performed well, to decreasing P concentration in Lake Taihu water in the presence of sediment. The EPC0 value, the critical P concentration at which there was neither P adsorption nor P release, was lowered by adding LMZ, suggesting that amendment with LMZ could diminish the risk of P release from the sediment. From the Langmuir isotherm model, the adsorption capacity of phosphate by LMZ was estimated to be 64.1 mgP/g. The LMZ-amended sediment had a higher content of stable P forms (HCl-P and Res-P) and a lower content of P forms with a high (NH4Cl-P and BD-P) or medium-high (NaOH-P and Org-P) risk of release, when compared with the original sediment. The fractionation simulates conditions which release potentially mobile P which can then be simply re-bound to LMZ. At high pH (>9.0), anaerobic condition or high temperature promoted the liberation of P from sediment. However, P release could be greatly inhibited by LMZ. In addition, although Mn2+ and NH4+ ions were released from sediment under the anaerobic condition, the release could also be hindered by adding LMZ. LMZ is a promising P inactivation agent to manage eutrophication in the sediment of Lake Taihu.


Subject(s)
Geologic Sediments/chemistry , Phosphorus/analysis , Water Pollutants, Chemical/analysis , Zeolites/chemistry , Adsorption , China , Environmental Restoration and Remediation , Eutrophication , Lakes/chemistry , Lanthanum , Phosphates , Phosphorus/chemistry , Water Pollutants, Chemical/chemistry
13.
Huan Jing Ke Xue ; 40(1): 310-317, 2019 Jan 08.
Article in Chinese | MEDLINE | ID: mdl-30628288

ABSTRACT

We studied the loading of N-(2-Aminoethyl)-3-aminopropyl trimethoxy silane from aqueous solution as a monolayer on magnetite nanoparticles and examined the phosphate removal performance of the generated adsorbent (silane monolayer on magnetite nanoparticles, abbreviated as MSMNPs). The results indicate that silane monolayer adsorption on magnetite nanoparticles occurred at low concentrations (equilibrium silane concentration <300 mg·L-1) and a~100% surface monolayer coverage by silane could be established at a temperature ≥ 90℃ or a NaCl concentration ≥ 0.1 mol·L-1. The FTIR and XPS spectra indicate that hydrolyzed silane and magnetite nanoparticles are chemically linked. The loading of silane as a monolayer did not significantly change the saturation magnetization. The adsorption isotherm of phosphate based on MSMNPs fit the Langmuir model better, with a calculated maximum adsorption capacity reaching 7.59 mg·g-1. The adsorption and desorption of phosphate by MSMNPs are very fast, exceeding 90% within 30 min and reaching an equilibrium within 1 h. In conclusion, MSMNPs are novel adsorbents with easy separability, which enables the repeated use, and rapid adsorption and desorption of pollutants.

14.
Oncol Lett ; 15(6): 8442-8446, 2018 Jun.
Article in English | MEDLINE | ID: mdl-29805580

ABSTRACT

The present study aimed to investigate the effect of fisetin on proliferation and apoptosis of gastric cancer cells, as well as the underlying mechanism. Proliferation in SGC7901 cancer and GES-1 normal cells was analyzed using a CCK-8 assay. Apoptosis was analyzed using an Annexin V/Propidium Iodide apoptosis kit and phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 was analyzed by western blot assay. Treatment of SGC7901 cells with various concentrations (1, 5, 10, 15 and 20 µM) of fisetin for 48 h resulted in a concentration dependent reduction in proliferation. Flow cytometry revealed a marked increase in apoptosis from 5 µM concentration of fisetin after 48 h. The percentage of apoptotic cells increased to 87% following treatment with 15 µM fisetin for 48 h, compared with 2% in control. Treatment of SGC7901 cells with fisetin for 48 h resulted in a reduction in the activation of ERK 1/2 in a concentration-dependent manner. The reduction in activation of ERK 1/2 was significant following treatment with 15 µM fisetin for 48 h. The inhibitory effect of fisetin on activation of ERK 1/2 was further demonstrated using the ERK 1/2 inhibitor, PD98059. The results indicated a significant reduction in the proliferation of SGC7901 cells following treatment with PD98059 (P<0.002). The reduction by PD98059 administration was comparable to that observed following fisetin treatment for 48 h. In conclusion, the current study demonstrates that fisetin inhibits the proliferation of gastric cancer cells and induces apoptosis through suppression of ERK 1/2 activation. Thus, fisetin may have therapeutic applications in the treatment of gastric cancer.

15.
J Lab Autom ; 21(4): 579-89, 2016 Aug.
Article in English | MEDLINE | ID: mdl-27094091

ABSTRACT

The electrochemistry reduction of coenzyme Q10 (CoQ10) on silver electrodes has been investigated in mixed solvent containing 95 vol. % ethanol and 5 vol. % water. A combination of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) is employed to explore the mechanism of redox processes of CoQ10 in the presence and absence of oxygen, respectively. It has been proved that the redox reaction of CoQ10 is highly dependent on the oxygen in the solution compared with that of CoQ0, which may be attributed to the isoprenoid side chain effect of CoQ10 Moreover, the effects of experimental variables such as electrolyte component, pH, temperature, and sonication time on the amperometric and potentiometric responses of CoQ10 are presented. The differential pulse voltammetry method has been developed for the quantification of the CoQ10 in the complex samples. Under the optimum conditions, the method is linear over the concentration range of 1.00 × 10(-7) to 1.00 × 10(-3) mol/L (8.63 × 10(-2) to 8.63 × 10(2) mg/kg). The limit of detection (3σ/k) is 3.33 × 10(-8) mol/L (2.88 × 10(-2) mg/kg). The recoveries of the spiked samples are between 91% and 108%. The presented method can be applied to the analysis of CoQ10 in real samples without any pretreatment.


Subject(s)
Electrochemistry/methods , Electrodes , Silver , Ubiquinone/analogs & derivatives , Ethanol , Oxidation-Reduction , Solutions , Solvents , Ubiquinone/analysis , Water
16.
Talanta ; 150: 503-9, 2016 Apr 01.
Article in English | MEDLINE | ID: mdl-26838436

ABSTRACT

Surface-Enhanced Raman scattering (SERS) has been widely used for imaging and sensing. However, limited reports are currently available on SERS-based cancer cell targeting strategy due to the challenge of synthesizing highly sensitive, reproducible and biocompatible SERS probe. Herein, we developed novel SERS probes, based on BSA (Bull Serum Albumin) coated gold-silver core-shell nanorods modified with Raman reporter 5,5-dithiobis 2-nitrobenzoic acid (DTNB) (Au@AgNRs@BSA@Anti-MICA), for in vitro cancer cell detection. Our results demonstrate that the SERS probe is very robust for cancer cell ultrasensitive detection with good biocompatibility and strong SERS signal.


Subject(s)
Gold/chemistry , Metal Nanoparticles/chemistry , Nanotubes/chemistry , Osteosarcoma/diagnosis , Serum Albumin, Bovine/chemistry , Silver/chemistry , Spectrum Analysis, Raman/methods , Animals , Bone Neoplasms/diagnosis , Cattle , Cell Proliferation , Humans , Male , Tumor Cells, Cultured
17.
J Lab Autom ; 20(4): 418-22, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25787806

ABSTRACT

The aim of this study was to identify an improved delivery scheme for intracellular delivery and anticancer therapy. Novel gold nanorods (GNRs) bioconjugates were prepared by using GNRs as nonviral vectors conjugated with thiol-modified antisense oligodeoxynucleotides (ASODNs). We then investigated the possibility of using GNRs as carriers for nucleus delivery of ASODNs genes by using confocal microscopy and cell transmission electron microscope imaging. Our results demonstrate that the GNRs-ASODNs entered into the cell nucleus and increased cell apoptosis. Therefore, the GNRs could hold great promise for biological delivery applications and gene therapy.


Subject(s)
Antineoplastic Agents/chemistry , Drug Carriers/chemistry , Gold/chemistry , Nanoconjugates/chemistry , Nanotubes/chemistry , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Cell Survival/drug effects , Drug Carriers/pharmacology , Gold/pharmacology , HeLa Cells , Humans
18.
Analyst ; 140(2): 623-9, 2015 Jan 21.
Article in English | MEDLINE | ID: mdl-25426959

ABSTRACT

A simple strategy to fabricate a fluorescent SiO2@zeolitic imidazolate framework-8 (ZIF-8) core-shell nanosensor for Cu(2+) detection was demonstrated in this work. The nanosensor was synthesized using carboxyl-functionalized SiO2 nanoparticles (SiO2 NPs) as a template to induce the growth of ZIF-8 on its surface. The porous SiO2@ZIF-8 exhibited extremely good adsorption properties and a large specific surface area to accumulate Cu(2+), and the pyridyl nitrogen sites in imidazole played vital roles in the recognition of Cu(2+). The fluorescent intensity decreased linearly with the increasing of Cu(2+) concentration in the range of 10-500 nM and the detection limit was estimated to be 3.8 nM. The SiO2@ZIF-8 nanosensor could be further used to determine trace amounts of Cu(2+) in real water samples, while some previous sensors had to be dispersed in organic solution for use, such as DMSO and MeCN. The core-shell nanostructures of SiO2@ZIF-8 made it possible for it to be dispersed directly in aqueous solution and prevented ZIF-8 from aggregation, which enhanced the sensing performance of the SiO2@ZIF-8 nanosensor.

19.
Biosens Bioelectron ; 63: 566-571, 2015 Jan 15.
Article in English | MEDLINE | ID: mdl-25168765

ABSTRACT

It is highly desirable to develop a simple and sensitive method for Hg(2+) detection because of the dangerous nature of Hg(2+). In this work, we prepared a dual-emission fluorescent probe for Hg(2+) detection by combining two lanthanide chelates with different emission wavelengths. Green-emitting terbium (Tb(3+)) chelates as reference signals were embedded into SiO2 nanoparticles and red-emitting europium (Eu(3+)) chelates as response units were covalently linked to the surface of silica shell. Upon the addition of Hg(2+), the fluorescence of Eu(3+) chelates can be selectively quenched, while the fluorescence of Tb(3+) chelates remained unchanged. As a kind of Hg(2+) nanosensor, the dual-emission fluorescent probe exhibited excellent selectivity to Hg(2+) and high sensitivity up to 7.07 nM detection limit. The Hg(2+) levels in drinking water and milk samples were determined by using the dual-emission fluorescent probe with satisfied recovery. Additionally, our probe has a long enough fluorescence lifetime, which can avoid the interference from autofluorescence of the biological samples. We envision that the proposed probe could find great potential applications for ultrasensitive time-resolved fluorometric assays and biomedical imaging in the future.


Subject(s)
Fluorescent Dyes/chemistry , Food Contamination/analysis , Lanthanoid Series Elements/chemistry , Mercury/analysis , Milk/chemistry , Spectrometry, Fluorescence/methods , Animals , Fluorescent Dyes/analysis , Food Analysis/methods , Lanthanoid Series Elements/analysis , Mercury/chemistry
20.
Analyst ; 139(21): 5516-22, 2014 Nov 07.
Article in English | MEDLINE | ID: mdl-25195570

ABSTRACT

Lanthanide coordination polymers have recently emerged as very fascinating sensing materials due to their tunable structures and unique optical properties. However, a major problem concerning the applications of lanthanide coordination polymers for fluorescent sensing is their unselective recognition to analytes. In this work, a direct post-modification strategy was employed to prepare functionalized lanthanide coordination polymer nanoparticles (Phe/Tb-CPBA CPNPs) with specific response ability to hydrogen peroxide (H2O2) by using phenylalanine (Phe) as bridging ligands, terbium ions (Tb(3+)) as metal nodes and carboxyphenylboronic acids (CPBAs) as guest ligands. Phe/Tb-CPBA CPNPs emit a strong green fluorescence due to the removal of coordinated water molecules and the sensitization effect of CPBA. Upon the addition of H2O2, however, the quenched fluorescence of Phe/Tb-CPBA CPNPs can be observed owing to an intramolecular charge transfer effect. This finding led to a method for the quantitation of H2O2 in the 6 µM to 1 mM concentration range and with a detection limit at 2 µM. Because of the chemoselective H2O2-mediated oxidative deboronation, Phe/Tb-CPBA CPNPs as fluorescent sensors exhibit excellent selectivity to H2O2. Furthermore, Phe/Tb-CPBA CPNPs were successfully used to measure the level of H2O2 in urine samples and showed satisfactory results. We envision that the presented strategy could be extended to design other functionalized coordination polymers with desired functions for various biomedical applications.


Subject(s)
Body Fluids/chemistry , Hydrogen Peroxide/analysis , Lanthanoid Series Elements/chemistry , Nanoparticles , Polymers/chemistry , Adult , Humans , Limit of Detection , Microscopy, Electron, Scanning , Spectroscopy, Fourier Transform Infrared
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