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1.
Sensors (Basel) ; 24(13)2024 Jul 05.
Article in English | MEDLINE | ID: mdl-39001158

ABSTRACT

Accurate weed detection is essential for the precise control of weeds in wheat fields, but weeds and wheat are sheltered from each other, and there is no clear size specification, making it difficult to accurately detect weeds in wheat. To achieve the precise identification of weeds, wheat weed datasets were constructed, and a wheat field weed detection model, YOLOv8-MBM, based on improved YOLOv8s, was proposed. In this study, a lightweight visual converter (MobileViTv3) was introduced into the C2f module to enhance the detection accuracy of the model by integrating input, local (CNN), and global (ViT) features. Secondly, a bidirectional feature pyramid network (BiFPN) was introduced to enhance the performance of multi-scale feature fusion. Furthermore, to address the weak generalization and slow convergence speed of the CIoU loss function for detection tasks, the bounding box regression loss function (MPDIOU) was used instead of the CIoU loss function to improve the convergence speed of the model and further enhance the detection performance. Finally, the model performance was tested on the wheat weed datasets. The experiments show that the YOLOv8-MBM proposed in this paper is superior to Fast R-CNN, YOLOv3, YOLOv4-tiny, YOLOv5s, YOLOv7, YOLOv9, and other mainstream models in regards to detection performance. The accuracy of the improved model reaches 92.7%. Compared with the original YOLOv8s model, the precision, recall, mAP1, and mAP2 are increased by 10.6%, 8.9%, 9.7%, and 9.3%, respectively. In summary, the YOLOv8-MBM model successfully meets the requirements for accurate weed detection in wheat fields.


Subject(s)
Plant Weeds , Triticum , Triticum/physiology , Plant Weeds/physiology , Neural Networks, Computer , Algorithms
2.
Anal Biochem ; 683: 115370, 2023 12 15.
Article in English | MEDLINE | ID: mdl-37890548

ABSTRACT

As the most well-known analytical tool, the thermometer has been extended to the field of biological analysis based on the photothermal effect. Herein, isoniazide modified Ag nanoparticles were prepared as nanolabels to build an immunoassay. The nanoparticles were characterized by transmission electron microscope (TEM), dynamic laser scattering (DLS), X-ray powder diffraction (XRD), and Fourier transform infrared (FT-IR). When the target protein was present, the sandwich immunoassay was developed and the photothermal reaction was triggered by isoniazide modified Ag nanoparticles. As a reducing agent, isoniazide is used to transform phosphomolybdic acid hydrate into molybdenum blue solution. And molybdenum blue had good photothermal stability and high photothermal conversion efficiency. The temperature variation of molybdenum blue solution showed a positive correlation with the concentration of carcinoembryonic antigen (CEA). Thus, the target protein of CEA was quantitative detection by thermometer. The linear response range is 0.1 ng mL-1 to 40 ng mL-1, and the detection limit is 0.08 ng mL-1. Moreover, the proposed protocol had satisfactory selectivity, accuracy, and reproducibility.


Subject(s)
Carcinoembryonic Antigen , Metal Nanoparticles , Carcinoembryonic Antigen/analysis , Reproducibility of Results , Spectroscopy, Fourier Transform Infrared , Silver , Immunoassay/methods , Limit of Detection , Gold
3.
Nanomaterials (Basel) ; 13(6)2023 Mar 20.
Article in English | MEDLINE | ID: mdl-36986006

ABSTRACT

Titanium and its alloys are widely used in high-end manufacturing fields. However, their low high-temperature oxidation resistance has limited their further application. Recently, laser alloying processing has attracted researchers to improve the surface properties of Ti, for which Ni coated graphite system is an excellent prospect due to its outstanding properties and metallurgical bonding between coating and substrate. In this paper, nanoscaled rare earth oxide Nd2O3 addition was added to Ni coated graphite laser alloying materials to research its influence on the microstructure and high-temperature oxidation resistance of the coating. The results proved that nano-Nd2O3 has an outstanding effect on refining coating microstructures, thus the high-temperature oxidation resistance was improved. Furthermore, with the addition of 1. 5 wt.% nano-Nd2O3, more NiO formed in the oxide film, which effectively strengthened the protective effect of the film. After 100 h of 800 °C oxidation, the oxidation weight gain per unit area of the normal coating was 14.571 mg/cm2, while that of the coating with nano-Nd2O3 addition was 6.244 mg/cm2, further proving that the addition of nano-Nd2O3 substantially improved the high-temperature oxidation properties of the coating.

4.
Materials (Basel) ; 15(18)2022 Sep 08.
Article in English | MEDLINE | ID: mdl-36143556

ABSTRACT

Ni35 coatings were fabricated on 45 steel using a CO2 laser at various parameters. A relatively large spot (10 mm diameter) was adopted, which was beneficial to the coating quality and the cladding efficiency. The cross-sectional geometry, phase constituent, and microstructure of the coatings were investigated. With a lower specific energy, coating height increased, while coating width, melted depth, dilution rate, width to height ratio and contact angle decreased. Ni35 coating primarily consisted of γ-Ni, FeNi3, Ni3B, Cr23C6, and Cr5B3. Dendrites with flower-like, fishbone-like, pearl-like, and column-like morphologies were observed. The fraction of flower-like dendrites increased gradually with the decrease in scanning velocity due to the dendrite growth direction evolution. With the decrease in scanning velocity, the microstructure of the heat-affected zone transformed from martensite to martensite + sorbite and finally sorbite. The maximum microhardness of the Ni35 coating reached 451.8 HV0.2, which was about double that of the substrate (220 HV0.2).

5.
Biomater Adv ; 136: 212772, 2022 May.
Article in English | MEDLINE | ID: mdl-35929311

ABSTRACT

W18O49-mediated photothermal therapy (PTT) is affected by the easily oxidized property and its direct exposure to physiological environment can cause biological events, which limit its development in the biomedical field. Herein, a composite nanoparticle PVP-W18O49@C (PW@C), with significant antioxidant and excellent biocompatibility, was constructed to overcome the limitations of W18O49 in the medical field. Oxygen-deficient W18O49, with irregular defect structure, was combined with hollow carbon nanospheres treated by reflux to obtain W18O49@C (W@C) similar to sea urchins. Compared with W18O49, W@C shows stronger antioxidant properties, and it still has the ability to convert light energy to heat energy after 6 months. In addition, polyvinyl pyrrolidone is coated on the surface of W@C to construct PW@C, which significantly improves biocompatibility of W@C. The photothermal conversion efficiency of PW@C was 42.9 ± 1.3. PWD (PW@C loaded with DOX·HCl) showed controllable drug release behavior under pH and NIR stimulation, and the drug release rate reached 69.1 ± 1.6% at pH = 5.0. Notably, PWD was readily absorbed by cells through clathrin/caveolae-mediated internalization channels, and the viability of HeLa cells treated with PWD + NIR was only 21.5 ± 1.0%. Through photothermal, drug delivery/release and cytotoxicity evaluation, PWD was proved to be an effective platform for chemo-/photothermal combinational tumor therapy.


Subject(s)
Hyperthermia, Induced , Nanospheres , Antioxidants , Drug Delivery Systems , HeLa Cells , Humans , Nanospheres/chemistry , Oxygen , Phototherapy , Photothermal Therapy
6.
Chron Respir Dis ; 19: 14799731221104099, 2022.
Article in English | MEDLINE | ID: mdl-36000309

ABSTRACT

Quality of life (QOL) in patients with Chronic obstructive pulmonary disease (COPD) is a major global concern in respiratory care with the specific instruments used rarely being developed using a modular approach. This paper is aimed to develop the COPD scale of the system of QOL Instruments for Chronic Diseases (QLICD-COPD) by the modular approach based on Classical Test Theory and Generalizability Theory (GT). 114 inpatients with COPD were used to provide the data measuring QOL three times before and after treatments. The psychometric properties of the scale were evaluated with respect to validity, reliability and responsiveness employing correlation analysis, factor analyses, multi-trait scaling analysis, and also GT analysis. The Results showed that Multi-trait scaling analysis, correlation and factor analyses confirmed good construct validity and criterion-related validity with almost all correlation coefficients or factor loadings being above 0.40. The internal consistency α and test-retest reliability coefficients (Pearson r and Intra-class correlations ICC) for all domains except for the social domain were larger than 0.70, ranging between 0.70-0.86 with r = 0.85 for the overall. The overall score and scores for physical and the specific domains had statistically significant changes after treatments with moderate effect size SRM (standardized response mean) ranging from 0.32 to 0.44. All G-coefficients and index of dependability were all greater than 0.80 exception of social domain (0.546 and 0.500 respectively), confirming the reliability of the scale further. It concluded that the QLICD-COPD has good validity, reliability, and moderate responsiveness, and can be used as the QOL instrument for patients with COPD.


Subject(s)
Pulmonary Disease, Chronic Obstructive , Quality of Life , Chronic Disease , Humans , Psychometrics/methods , Reproducibility of Results , Surveys and Questionnaires
7.
Talanta ; 249: 123665, 2022 Nov 01.
Article in English | MEDLINE | ID: mdl-35691125

ABSTRACT

A photothermal immunoassay was built for tumor marker detection based on Ag4P2O7@Ag nanocomposites. Ag4P2O7@Ag nanomaterials were synthesized by precipitation-photoreduction reaction, and characterized by transmission electron microscope (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectra (XPS) and X-ray powder diffraction (XRD). Come about PO43- derived from Ag4P2O7@Ag under acidic conditions react with ammonium molybdate in the action of reductant generating molybdenum blue. The photothermal change is due to molybdenum blue solution depending on the concentration of carcinoembryonic antigen (CEA) in immunoassay. Under optimal conditions, there is a linear relation between ΔT and CEA concentration in the range of 1 pg mL-1-40 ng mL-1 with the detection limit of 0.33 pg mL-1. Meanwhile, the developed photothermal immunoassay displays preferable selectivity, repeatability, and stability.


Subject(s)
Carcinoembryonic Antigen , Nanocomposites , Immunoassay , Limit of Detection , Molybdenum
8.
Int J Pharm ; 623: 121912, 2022 Jul 25.
Article in English | MEDLINE | ID: mdl-35710074

ABSTRACT

In this study, a biodegradable multifunctional photothermal drug delivery nanoparticles (MPH NPs) using curcumin (Cur) as the ligand coated with hyaluronic acid (HA) was successfully prepared, which could simultaneously deliver Cur and doxorubicin hydrochloride (DOX·HCl) to overcome the common drug resistance in cancer cells. Polydopamine (PDA) as a protective shell prevents premature degradation of Cur in physiological environment and enables it to play effective medicinal value. MPH NPs can specifically recognize CD44 receptors on the surface of cancer cells for tumor targeting, with the damage of the partially released DOX to the superficial tumor cells, and then the positively charged Cur released may gradually penetrate into the cells through electron interaction to improve the problem of low permeability. In vitro cell experiments showed that hydrophobic/hydrophilic drugs co-loaded MPDH (MPH loaded with DOX·HCl) could enter the cancer cells through the endocytosis mediated by clathrin / caveolin, and the inhibition rate of MPDH on HeLa cells reached 79.28 % irradiation under 808 nm laser. MPH were composed of safe materials that have been proven to be biodegradable in human body, which avoided the disadvantages that NPs were difficult to discharge and caused damage to normal organs during long-term use.


Subject(s)
Curcumin , Nanoparticles , Cell Line, Tumor , Doxorubicin/pharmacology , Doxorubicin/therapeutic use , Drug Liberation , HeLa Cells , Humans , Indoles , Pharmaceutical Preparations , Phototherapy , Photothermal Therapy , Polymers , Precision Medicine , Theranostic Nanomedicine
9.
BMJ Open Respir Res ; 9(1)2022 05.
Article in English | MEDLINE | ID: mdl-35545296

ABSTRACT

BACKGROUND: The Quality of Life Instrument for Chronic Diseases (QLICD)-COPD (V2.0) was designed to assess the health condition of patients with chronic obstructive pulmonary disease (COPD). The objective of this study was to evaluate the quality of life (QOL) of patients, the influential clinical factors and the relationships between QOL and clinical objective indicators. METHODS: Two hundred and sixty-one inpatients with COPD in the acute exacerbation stage were evaluated using the QLICD-COPD (V2.0) and data on clinical objective indicators were collected. The relationships between QOL and the clinical objective indicators were determined using canonical correlation analysis. RESULTS: The standardised scores for the patients in four domains, namely, physical function, psychological function, social function and a disease-specific module, were 49.00±12.91, 59.89±13.51, 68.59±11.94 and 51.84±13.58, respectively. The total score for the QOL of patients was 57.17±10.26. Two pairs of canonical variables were statistically significant (r1=0.35, p<0.0001; r2=0.26, p<0.05). These variables accounted for 45.8% and 33.8% of the variance, respectively. The levels of total protein, albumin, serum sodium and alkaline phosphatase and the percentages of neutrophils and lymphocytes were correlated with the QOL, with correlation coefficients ranging from -0.435 to 0.675. CONCLUSION: Clinicians should pay close attention to the levels of total protein, albumin, serum sodium and alkaline phosphatase and the percentages of neutrophils and lymphocytes to improve the QOL of patients.


Subject(s)
Pulmonary Disease, Chronic Obstructive , Quality of Life , Alkaline Phosphatase , Canonical Correlation Analysis , Humans , Quality of Life/psychology , Serum Albumin , Sodium , Surveys and Questionnaires
10.
Mikrochim Acta ; 188(3): 63, 2021 02 03.
Article in English | MEDLINE | ID: mdl-33537897

ABSTRACT

A photothermal immunoassay using a thermometer as readout based on polyaniline@Au organic-inorganic nanohybrids was built. Temperature output is acquired due to the photothermal effect of the photothermal nanomaterial. Polyaniline@Au organic-inorganic nanohybrids were synthesized by interfacial reactions with high photothermal conversion efficiency. A sandwich structure of the immunocomplex was prepared on a microplate for determination of carcinoembryonic antigen (CEA) by polyaniline@Au organic-inorganic nanohybrids as nanolabel. The released heat based on light-to-heat conversion from the photothermal nanolabel under NIR irradiation is detectable using the thermometer. The increased temperature is directly proportional to CEA concentration. The linear range of the photothermal immunoassay is 0.20 to 25 ng mL-1 with determination limit of 0.17 ng mL-1. Polyaniline@Au organic-inorganic nanohybrids with high photothermal conversion efficiency was synthesized as labels to construct photothermal immunosensor. The sandwich-type immunoassay was built on 96 hole plate based on specific binding of antigen and antibody. Carcinoembryonic antigen in sample was detected quantitatively by thermometer readout.


Subject(s)
Biomarkers, Tumor/blood , Carcinoembryonic Antigen/blood , Immunoassay/methods , Nanocomposites/chemistry , Thermometers , Aniline Compounds/chemistry , Aniline Compounds/radiation effects , Animals , Antibodies, Monoclonal/immunology , Biomarkers, Tumor/immunology , Carcinoembryonic Antigen/immunology , Gold/chemistry , Gold/radiation effects , Humans , Immunoassay/instrumentation , Infrared Rays , Limit of Detection , Nanocomposites/radiation effects , Rabbits , Reproducibility of Results , Temperature
11.
Colloids Surf B Biointerfaces ; 192: 111054, 2020 Apr 18.
Article in English | MEDLINE | ID: mdl-32335496

ABSTRACT

The three-dimensional urchin-like MoS2@C nanocomposite was successfully synthesized via one-step hydrothermal synthesis approach. The as-prepared MoS2@C nanoparticles exhibits strong absorb, high photothermal conversion ability (40.8 %), superb biocompatibility and high drug loading capacity for doxorubicin (52.34 %). In vitro drug release experiments show a pH, temperature and near infrared laser-triggered doxorubicinhydro release profile that enhances therapeutic anticancer effects. The drug release curve increased step by step under laser irradiation, and the accumulative delivery amount reached to 64.59 %, which was about 2 times of that without laser irradiation. By using DOX-loaded nano-platform, effective synergistic photothermal therapy for cancer can be achieved and has been systematically verified in vitro. Cell viability experiments showed that the survival rate of cells with MoS2 @C-DOX was only 25.8 %. Therefore, this work presents carbon-based nanoparticles with significant characteristics and is used as a highly potential therapeutic nano-platform for cancer treatment.

12.
Polymers (Basel) ; 12(3)2020 Mar 04.
Article in English | MEDLINE | ID: mdl-32143480

ABSTRACT

A hybrid polymer of SiO2@Tb3+(poly(ethylene terephthalate)-tetraglycol)3 phenanthroline (SiO2@Tb3+(PET-TEG)3Phen) was synthesized by mixing of inorganic SiO2 nanoparticles with polymeric segments of PET-TEG, whereas PET-TEG was achieved through multi-step functionalization strategy. Tb3+ ions and ß-diketonate ligand Phen were added in resulting material. The experimental results demonstrated that it was well blended with PET as a robust additive, and not only promoted the crystallinity, but also possessed excellent luminescence properties. An investigation of the mechanism revealed that the SiO2 nanoparticles functioned as a crystallization promotor; the Tb3+ acted as the fluorescent centre; and the PET-TEG segments played the role of linker and buffer, providing better compatibility of PET matrix with the inorganic component. This work demonstrated that hybrid polymers are appealing as multifunctional additives in the polymer processing and polymer luminescence field.

13.
J Nanosci Nanotechnol ; 20(2): 779-788, 2020 02 01.
Article in English | MEDLINE | ID: mdl-31383073

ABSTRACT

N and F co-doped La-TiO2 (La-TONF) samples were prepared through the solvothermal method by using HMT and NaF as precursors. The obtained samples were characterized by UV-Vis DRS, XRD, XPS and PL measurements for light-harvesting properties, crystal phase and optical characteristics, respectively. Interestingly, the TONF sample had a different fluorescence emission intensity than the TON or TOF samples, thus suggesting a clear synergistic effect of N and F co-doping. The optimal doping amount of La was 2 wt.%, and the absorption edge was red-shifted from 453 nm to 464 nm for La-TiO2 and La-TONF. The photocatalytic activity was evaluated by degradation of MO and oxidation of TMB under visible light irradiation. La-TONF exhibited excellent photocatalytic activity and a degradation rate of 92.4%, 4.4 times that of undoped TiO2 (20.8%). The photocatalytic degradation activity remained above 85.8%, even after five runs. In addition, the MO photodegradation catalyzed by La-TONF followed first order kinetics. According these results, a possible synergistic effect mechanism for the enhanced photocatalytic performance is proposed.

14.
Mikrochim Acta ; 186(9): 633, 2019 08 18.
Article in English | MEDLINE | ID: mdl-31422485

ABSTRACT

A sensitive photoelectrochemical (PEC) immunoassay for the carcinoembryonic antigen (CEA) is described that is based on the use of C3N4-BiOCl semiconductor on an ITO electrode. The photocurrent of the modified electrode was measured under visible light illumination. It increased in presence of L-cysteine due to rapid separation of the photoexcited electrons and holes. A sandwich-type immunoassay in a 96-well microtiter plate format used CuO nanoparticles as label for the secondary antibody. The Cu2+ is released from the CuO in the sandwich complex by treatment with acid. The free Cu2+ combined with both the cysteine and the electron receptors of C3N4 and BiOCl. Under optimal conditions, this dual action immensely decreases the photocurrent of the PEC system, and the response is inversely proportional to the CEA concentrations from 0.1 pg mL-1 to 10 ng mL-1 at the working voltage of 0 V (vs. SCE). The detection limit is 0.1 pg mL-1, and the method is exhibited satisfactory selective, repeatable and stable. Graphical abstract Schematic representation of an immunoassay based on cysteine-assisted C3N4-BiOCl photoelectrochemical platform. CuO nanoparticles were utilized as labels in immunocomplex to release Cu2+ in acidic condition. Carcinoembryonic antigen in sample was detected sensitively by dual function of Cu2+ with cysteine and C3N4-BiOCl semiconductor.


Subject(s)
Antibodies/chemistry , Biosensing Techniques , Carcinoembryonic Antigen/analysis , Cysteine/chemistry , Electrochemical Techniques , Enzyme-Linked Immunosorbent Assay , Semiconductors , Antibodies/immunology , Antigen-Antibody Reactions , Bismuth/chemistry , Carcinoembryonic Antigen/immunology , Copper/chemistry , Electrodes , Graphite/chemistry , Humans , Nanoparticles/chemistry , Nitrogen Compounds/chemistry , Particle Size , Photochemical Processes , Surface Properties
15.
J Pharm Biomed Anal ; 169: 75-81, 2019 May 30.
Article in English | MEDLINE | ID: mdl-30844625

ABSTRACT

A simple colorimetric immunoassay based on visible light excitation for detection of carcinoembryonic antigen (CEA) was developed. Firstly, visible light photocatalysts of TiO2/SnOx-Au ternary heterostructures were prepared by in situ reduction method, which were characterized using transmission electron microscope (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray powder diffraction (XRD) and UV-vis diffuse reflectance spectroscopy (DRS). Then, a novel sandwich-type colorimetric immunoassay for quantitative analysis of CEA by using TiO2/SnOx-Au nanoparticle as signal tag was constructed. Under visible light irradiation (λ ≥ 420 nm), the color development of TMB was obtained. And the quantitative analysis was carried out in ABS buffer solution by ultraviolet spectrum scanning. Under optimal conditions, the absorbance values increased with the increasing of CEA levels in samples, which presented linear relationship in the range of 5 pg mL-1-2.5 ng mL-1 with a detection limit of 5 pg mL-1. Meanwhile, the colorimetric immunosensor owned acceptable specificity, stability and reproducibility.


Subject(s)
Biomarkers, Tumor/chemistry , Gold/chemistry , Metal Nanoparticles/chemistry , Nanocomposites/chemistry , Titanium/chemistry , Carcinoembryonic Antigen/chemistry , Catalysis , Colorimetry/methods , Immunoassay/methods , Limit of Detection , Reproducibility of Results , X-Ray Diffraction/methods
16.
Mikrochim Acta ; 185(12): 530, 2018 11 06.
Article in English | MEDLINE | ID: mdl-30402791

ABSTRACT

The authors describe an amplified photoelectrochemical immunoassay for the tumor marker carbohydrate antigen 724 (CA724). The method employs a C3N4-MoS2 semiconductor as the photoelectric conversion layer. The nanocomposite was characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray powder diffraction, and UV-vis diffuse reflectometry. The dye eosin Y was encapsulated into CaCO3 nanospheres which then were used as labels for antibody against CA724. In addition, Fe3O4 nanospheres were employed as magnetic platform for constructing photoelectrochemical sandwich immunoassay. The CaCO3 nanospheres can be dissolved with aid of ethylene diamine tetraacetic acid (EDTA) and the carried eosin Y in CaCO3 is released. The released dyes sensitizes the C3N4-MoS2 semiconductor, which induces photocurrent amplification. Under optimal conditions and at a typical working voltage of 0 V (vs. SCE), the photocurrent increases linearly in the range of 0.05 mU mL-1 to 500 mU mL-1 of CA724, with a 0.02 mU mL-1 detection limit. Graphical abstract The C3N4-MoS2 complex, with high efficiency of electron transport, was synthesized to construct a photoelectrochemical analytical platform. A sandwich-type immunoassay was established on the surface of magnetic beads. Carbohydrate antigen 724 in sample was detected sensitively by using sensitization of released eosin Y as signal amplifiery.


Subject(s)
Antigens, Tumor-Associated, Carbohydrate/analysis , Coloring Agents/chemistry , Disulfides/chemistry , Immunoassay/instrumentation , Molybdenum/chemistry , Nitriles/chemistry , Photochemical Processes , Semiconductors , Edetic Acid/chemistry , Electrochemistry , Ferrosoferric Oxide/chemistry , Humans , Limit of Detection , Models, Molecular , Molecular Conformation
17.
Mikrochim Acta ; 185(6): 310, 2018 06 01.
Article in English | MEDLINE | ID: mdl-29858657

ABSTRACT

The authors describe a dye-sensitized photoelectrochemical immunoassay for the tumor marker carcinoembryonic antigen (CEA). The method employs the rhodamine dye Rh123 with red color and absorption maximum at 500 nm for spectral sensitization, and a 3D nanocomposite prepared from graphene oxide and MoS2 acting as the photoelectric conversion layer. The nanocomposite with flower-like 3D architectures was characterized by transmission electron microscopy, scanning electron microscopy, X-ray powder diffraction, and UV-vis diffuse reflectometry. A photoelectrochemical sandwich immunoassay was developed that is based on the use of the nanocomposite and based on the specific binding of antibody and antigen, and by using a secondary antibody labeled with Rh123 and CdS (Ab2-Rh123@CdS). Under optimal conditions and at a typical working voltage of 0 V (vs. Hg/HgCl2), the photocurrent increases linearly 10 pg mL-1 to 80 ng mL-1 CEA concentration range, with a 3.2 pg mL-1 detection limit. Graphical abstract Flower-like GO-MoS2 complex with high efficiency of electron transport was synthesized to construct photoelectrochemical platform. The sandwich-type immunoassay was built on this platform based on specific binding of antigen and antibody. Carcinoembryonic antigen in sample was detected sensitively by using sensitization of rhodamine dye Rh123 as signal amplification strategy.

18.
J Nanosci Nanotechnol ; 18(5): 3306-3313, 2018 May 01.
Article in English | MEDLINE | ID: mdl-29442832

ABSTRACT

Fly ash is a solid waste discharged from thermal power plant. Specific surface area of floating fly ash cenospheres (FACs) would increase after it was modified. The photocatalytic composite of TiO2/FACs was successfully synthesized by sol-gel method using the carrier of modified FACs and tetrabutyl titanate as starting materials. The different influence factors on the photocatalytic performance of TiO2/FACs composites were characterized through SEM, EDS, XRD, UV-vis DRS and BET surface measurements. The UV-vis DRS spectra revealed that the absorption edge of TiO2 is 387 nm while that of TiO2/FACs photocatalysts red-shifts to 500 nm. Photocatalytic activity of TiO2/FACs was evaluated by the photocatalytic depigmentation of methyl orange solution (MO, 20 mg L-1, pH = 6.3) under visible light irradiation. It was found that the specific surface area, surface roughness and activity of FACs were increased by NaOH solution activation. The degradation rate of MO reaches 52% in 180 min under the visible light illumination. But too much FACs could decrease its photocatalytic activity and degradation rate. And the recovery test indicated that TiO2/FACs photocatalyst was rather stable, easy to recover from the treated wastewater.

19.
J Nanosci Nanotechnol ; 18(3): 1675-1681, 2018 Mar 01.
Article in English | MEDLINE | ID: mdl-29448644

ABSTRACT

Metal ions (Cr, Ni, Co) doped titania (M-TiO2) coupled with the long after glow phosphor MgAl2O4:(Pr3+, Dy3+) particles were synthesized by the sol-gel method, with the best mass ratio of MgAl2O4:(Pr3+, Dy3+) to M-TiO2 as 4:6. MgAl2O4:(Pr3+, Dy3+)/M-TiO2 had the persistent methyl orange (MO) photocatalytic degradation ability and the photocatalytic degradation went on reacting more than 90 min in dark after turning off the light. MgAl2O4:(Pr3+, Dy3+) emitted the light as a light source in dark which was absorbed by M-TiO2. The differences of MgAl2O4:(Pr3+, Dy3+)/Cr-TiO2, MgAl2O4:(Pr3+, Dy3+)/Ni-TiO2 and MgAl2O4:(Pr3+, Dy3+)/Co-TiO2 might be attributed to the difference in the metal ions doping. The composite MgAl2O4:(Pr3+, Dy3+)/Cr-TiO2 revealed the highest ability of persistent photocatalytic degradation methyl orange. Different metal ions doping made the TiO2 with different band gap.

20.
Water Sci Technol ; 78(11): 2321-2327, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30699083

ABSTRACT

Using tetra-n-butyl titanate as raw material and fly ash cenospheres (FAC) as carrier, the photocatalysts of Ag-TON/FAC were successfully prepared by solvothermal and in-situ hydrolysis method. These visible light photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), fluorescence spectroscopy (FL) and UV-vis diffuse reflectance spectra (DRS). In this study, methyl orange and ciprofloxacin were used as wastewater degradation targets to investigate the effect of the amount of titanium dioxide and the amount of Ag doping on the activity of photocatalysts. On the basis of this, the optimal ratio of TiO2 to FAC was 2:1 and the optimum doping ratio of Ag was determined to be 15 wt.%. The composite photocatalysts dispersed uniformly and were easy to recycle and reuse, which were benefits in fully utilizing the solar energy. The degradation efficiency remained at more than 60% after being renewed five times for MO and ciprofloxacin. The photocatalysts of Ag-TON/FAC can reduce the environmental burden caused by FAC also.


Subject(s)
Coal Ash/chemistry , Nanospheres , Waste Disposal, Fluid/methods , Catalysis , Light , Silver , Titanium , Wastewater
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