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1.
Mikrochim Acta ; 190(7): 268, 2023 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-37338607

RESUMO

A novel fluorescent strategy has been developed by using an enzymatic reaction modulated DNA assembly on graphitic carbon nitride nanosheets (CNNS) for the detection of acetylcholinesterase (AChE) activity and its inhibitors. The two-dimensional and ultrathin-layer CNNS-material was successfully synthesized through a chemical oxidation and ultrasound exfoliation method. Because of its excellent adsorption selectivity to ssDNA over dsDNA and superior quenching ability toward the fluorophore labels, CNNS were employed to construct a sensitive fluorescence sensing platform for the detection of AChE activity and inhibition. The detection was based on enzymatic reaction modulated DNA assembly on CNNS, which involved the specific AChE-catalyzed reaction-mediated DNA/Hg2+ conformational change and subsequent signal transduction and amplification via hybridization chain reaction (HCR). Under the excitation at 485 nm, the fluorescence signal from 500 to 650 nm (λmax = 518 nm) of the developed sensing system was gradually increased with increasing concentration of AChE. The quantitative determination range of AChE is from 0.02 to 1 mU/mL and the detection limit was 0.006 mU/mL. The developed strategy was successfully applied to the assay of AChE in human serum samples, and can also be used to effectively screen AChE inhibitors, showing great promise providing a robust and effective platform for AChE-related diagnosis, drug screening, and therapy.


Assuntos
Acetilcolinesterase , Grafite , Humanos , Fluorescência , DNA , Grafite/química
2.
Environ Res ; 215(Pt 1): 114190, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36049509

RESUMO

Heterojunction-driven photocatalysis can degrade various organic pollutants, and developing carbon nitride-based composite photocatalysts is of great significance and gains growing interest. In this study, a two-dimensional graphitic carbon nitride nanosheets/BiFeO3 (GCNNs/BiFeO3) Z-scheme heterojunction has been synthesized through the electrostatic spinning and post-calcination The obtained GCNNs/BiFeO3 nanofibers show large surface contact between GCNNs the and BiFeO3 nanostructures. The Z-scheme heterojunction shows a remarkably enhanced photocatalytic performance, which could degrade 94% of tetracycline (TC) and 88% of Rhodamine B (RhB) under LED visible light irradiation in 150 min. Radical trapping experiments demonstrate the effective construction of Z-scheme heterojunctions, and •O2- and h+ are the main active species in the photocatalytic degradation process. This study realizes a novel nanostructured GCNNs/BiFeO3 heterojunction for photodegradation applications, which would guide the design of next-generation efficient photocatalysts.


Assuntos
Poluentes Ambientais , Catálise , Nitrilas , Fotólise , Tetraciclina/química
3.
Mikrochim Acta ; 187(5): 279, 2020 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-32314246

RESUMO

A "half" core-shell g-C3N4/Fe3O4@ZIF-8 nanohybrid, in which Fe3O4 and zeolite imidazolate framework-8 (ZIF-8) constructed the core-shell structure, was successfully fabricated via a versatile in situ growth strategy. This nanohybrid was employed for simultaneous magnetic solid-phase extraction (MSPE) of trace levels of fifteen target sulfonylurea herbicides (SUHs) in environmental water samples followed by LC-MS/MS detection. C3N4 nanosheets were first prepared by liquid exfoliation of bulk g-C3N4, after which Fe3O4 nanoparticles were uniformly deposited onto the surface of C3N4 nanosheets, and ZIF-8 nanoparticles were grown on the surface of g-C3N4/Fe3O4 by anchoring Zn2+ on g-C3N4/Fe3O4. Owing to the synergistic effect, the hybridization of C3N4 and ZIF-8 endowed the nanohybrid with higher multi-target adsorption ability for SUHs compared to pure C3N4 or ZIF-8. The separation as well as the enrichment processes were facilitated using Fe3O4 as a magnetic core. The influence of various parameters on MSPE efficiency, including adsorbent dosage, extraction time, solution pH, and desorption solvent and its volume, was investigated in detail. Under optimal conditions, the MSPE coupled with LC-MS/MS exhibited good linearity ranging from 0.5 to 100 µg L-1 with correlation coefficients (R2) ≥ 0.9919, high sensitivity with low limits of detection (LODs) of 0.005-0.141 µg L-1 and satisfactory recoveries of 67.4-105.5% with relative standard deviations (RSDs) < 9.8%. These results indicate that this method is reliable for the determination of SUHs in different matrices and the in situ growth strategy is a promising approach for constructing effective adsorbents. Graphical abstract Schematic representation of a "half" core-shell magnetic nanohybrid composed of zeolitic imidazolate framework (ZIF-8) and graphitic carbon nitride (g-C3N4) for magnetic solid-phase extraction (MSPE) of trace level determination of fifteen sulfonylurea herbicides (SUHs) in environmental water samples using LC-MS/MS detection.

4.
Sensors (Basel) ; 20(21)2020 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-33114675

RESUMO

A simple one-step electrochemical deposition/activation of graphitic carbon nitride (g-C3N4) is highly desired for sensor configurations and remains a great challenge. Herein, we attempt an electrochemical route to exfoliate the g-C3N4 nanosheets in an aqueous solution of pH 7.0 for constructing a sensor, which is highly sensitive for the detection of serotonin (5-HT). The significance of our design is to exfoliate the g-C3N4 nanosheets, a strong electrocatalyst for 5-HT detection. Investigations regarding the effect of neutral pH (pH 7.0) on the bulk g-C3N4 and g-C3N4 nanosheets, physical characterization, and electrochemical studies were extensively carried out. We demonstrate that the g-C3N4 nanosheets have a significant electrocatalytic effect for the 5-HT detection in a dynamic linear range from 500 pM to 1000 nM (R2 = 0.999). The limit of detection and sensitivity of the designed 5-HT sensor was calculated to be 150 pM and 1.03 µA µM-1 cm-2, respectively. The proposed sensor has great advantages such as high sensitivity, good selectivity, reproducibility, and stability. The constructed g-C3N4 nanosheets-based sensor platform opens new feasibilities for the determination of 5-HT even at the picomolar/nanomolar concentration range.


Assuntos
Carbono , Serotonina , Análise Custo-Benefício , Eletrodos , Grafite , Nitrilas , Compostos de Nitrogênio , Reprodutibilidade dos Testes , Serotonina/análise
5.
J Sep Sci ; 41(9): 2020-2028, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29420870

RESUMO

A green biocomposite of sunflower stalks and graphitic carbon nitride nanosheets has been applied as a solid-phase extraction adsorbent for sample preparation of five polycyclic aromatic hydrocarbons in different solutions using high-performance liquid chromatography with ultraviolet detection. Before the modification, sunflower stalks exhibited relatively low adsorption to the polycyclic aromatic hydrocarbons extraction. The modified sunflower stalks showed increased adsorption to the analytes extraction due to the increase in surface and existence of a π-π interaction between the analytes and graphitic carbon nitride nanosheets on the surface. Under the optimal conditions, the limits of detection and quantification for five polycyclic aromatic hydrocarbons compounds could reach 0.4-32 and 1.2-95 ng/L, respectively. The method accuracy was evaluated using recovery measurements in spiked real samples and good recoveries from 71 to 115% with relative standard deviations of <10% have been achieved. The developed method was successfully applied for polycyclic aromatic hydrocarbons determination in various samples-well water, tap water, soil, vegetable, and barbequed meat (kebab)-with analytes contents ranging from 0.065 to 13.3 µg/L. The prepared green composite as a new sorbent has some advantages including ease of preparation, low cost, and good reusability.

6.
Food Chem ; 439: 138158, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38071846

RESUMO

Total antioxidant capacity (TAC) is vital for food quality evaluation. The emergence of various nanozymes with TMB as substrate offered a new avenue for TAC detection due to simple operation and fast response, but a long-standing challenge is its low activity at physiological pH, which may account for the discrepancy between the measured TAC and the actual antioxidant capacity in vivo. Herein, Au doping was explored to break the pH limitation of g-C3N4 nanosheets (CNNS) photozyme. The catalytic activities of Au@CNNS at pH 4.0 and 7.4 were 14.9- and 6.2-fold higher than that of CNNS at pH 4. The neutral pH photozymatic activity (photosensitized oxidation of TMB, oxidase mimic) of Au@CNNS was explored for sensitivity TAC detection (LOD: 1.0 µM TE), which featured more convenient operations and higher sensitivity over the DPPH assay. The proposed Au@CNNS-based photozymatic colorimetric method was explored for accurate detection of TAC in drinks and juices.


Assuntos
Antioxidantes , Colorimetria , Colorimetria/métodos , Oxirredução , Concentração de Íons de Hidrogênio
7.
ACS Appl Bio Mater ; 7(3): 1579-1587, 2024 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-38386014

RESUMO

In this study, a nanocomposite was synthesized by incorporating graphitic carbon nanosheets, carboxyl-functionalized multiwalled carbon nanotubes, and zirconium oxide nanoparticles. The resulting nanocomposite was utilized for the modification of a glassy carbon electrode. Subsequently, matrix metalloproteinase aptamer (AptMMP-9) was immobilized onto the electrode surface through the application of ethyl-3-(3-(dimethylamino)propyl)carbodiimide hydrochloride-N-hydroxysuccinimide (EDC-NHS) chemistry. Morphological characterization of the nanomaterials and the nanocomposite was performed using field-emission scanning electron microscopy (FESEM). The nanocomposite substantially increased the electroactive surface area by 205%, facilitating enhanced immobilization of AptMMP-9. The efficacy of the biosensor was evaluated using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Under optimal conditions, the fabricated sensor demonstrated a broad range of detection from 50 to 1250 pg/mL with an impressive lower limit of detection of 10.51 pg/mL. In addition, the aptasensor exhibited remarkable sensitivity, stability, excellent selectivity, reproducibility, and real-world applicability when tested with human serum and saliva samples. In summary, our developed aptasensor exhibits significant potential as an advanced biosensing tool for the point-of-care quantification of MMP-9, promising advancements in biomarker detection for practical applications.


Assuntos
Aptâmeros de Nucleotídeos , Grafite , Nanocompostos , Nanotubos de Carbono , Compostos de Nitrogênio , Zircônio , Humanos , Nanotubos de Carbono/química , Metaloproteinase 9 da Matriz , Técnicas Eletroquímicas/métodos , Saliva , Reprodutibilidade dos Testes , Limite de Detecção , Aptâmeros de Nucleotídeos/química , Nanocompostos/química
8.
ACS Appl Mater Interfaces ; 15(23): 28626-28635, 2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-37276584

RESUMO

The application of high-performance thermal interface materials (TIMs) for thermal management is commonly used to tackle the problem of heat accumulation, which influences the performance and reliability of microelectronic devices. Herein, a novel three-dimensional (3D) carbon nitride nanosheet (CNNS)/epoxy composite with high thermal conductivity was developed by introducing 3D CNNS skeleton fillers prepared by a facile and scalable strategy assisted by a salt template. Benefiting from the continuous heat transfer pathways formed in the CNNS skeleton, 17.0 wt % 3D CNNS/epoxy composites achieve a superior thermal conductivity of 1.27 W/m·K, which is 6.35 and 1.57 times higher than those of epoxy resin and convention CNNS/epoxy, respectively. With the aid of theoretical model analysis and finite element simulation, the pronounced enhancement effect of the 3D CNNS skeleton on the thermal conductivity of epoxy composites is found to be attributed to the continuous 3D CNNS thermally conductive network, the diminished CNNS-CNNS interfacial thermal resistance, and the effective interfacial interactions between epoxy and CNNS. In addition, the 3D CNNS/epoxy composites possess high electrical insulation and desirable mechanical strength. Therefore, 3D CNNS/epoxy composites are promising TIMs for advanced electronic thermal management.

9.
Polymers (Basel) ; 14(3)2022 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-35160375

RESUMO

Breakdown strength is an important parameter for polymer dielectric, and introducing inorganic filler into the polymer matrix is an efficient method to improve the breakdown strength. In this work, graphitic carbon nitride nanosheets (CNNS) were ultrasonically exfoliated and coated with polydopamine to obtain modified nanosheets (DCNNS), and then polyimide (PI) composite films with various CNNS and DCNNS were prepared and compared. Owing to the abundant hydroxyl groups of polydopamine, good filler-polymer compatibility and uniform filler dispersion were achieved for PI/DCNNS composites. Both breakdown strength and dielectric constant were improved with the addition of either CNNS or DCNNS. However, at the same filler content, the PI/DCNNS composites exhibited higher breakdown strength and dielectric constant than the PI/CNNS. The PI composite with 0.5 wt% DCNNS showed the highest breakdown strength of ~300 kV/mm, increased by 67.6% as compared to the pure PI, while the PI/CNNS composite with the same filler content only increased by 14.5%.

10.
Sci Total Environ ; 851(Pt 2): 158360, 2022 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-36041623

RESUMO

Post thermal treatment of bulk graphitic carbon nitride (g-C3N4) by ammonia gas acts as a significant structure regulation approach, while pure ammonia-assisted g-C3N4 synthesis from precursors like melamine is rarely investigated. Here we prove the synthesis of N-defects abundant carbon nitride nanosheets (ACN) through a one-pot thermal polymerization of melamine in pure ammonia gas, for photocatalytic organic pollutant removal in water and H2 evolution applications. Compared to bulk g-C3N4 (BCN), ACN-550 (ACN prepared at 550 °C) exhibited thin-layered porous morphology with higher surface area and abundant N defects, resulting in wider distribution of active sites. Moreover, the abundant N defects in the heptazine heterocycle structure could change the electronic structure of g-C3N4, leading to more efficient transport of photogenerated charge carriers and enhanced photoreduction potential, which gives rise to notable improvement activities in photocatalytic reaction. With superoxide ion radical and photoinduced holes as the predominant reactive species, ACN-550 realized efficient photocatalytic bisphenol A (BPA) degradation, which is 1.6- and 4.7-fold high over commercial TiO2 (P25) and BCN, respectively. ACN-550 exhibited excellent reusability and stability in five consecutive photocatalytic BPA degradation tests. In photo-reductive H2 production system by ACN-550, 761.8 ± 4.3 µmol/h/g H2 was produced, which was 11.6-fold as high as that by BCN.


Assuntos
Poluentes Ambientais , Amônia , Catálise , Superóxidos , Água
11.
Methods Appl Fluoresc ; 10(4)2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-35850115

RESUMO

Silver is widely used in medical materials, photography, electronics and other industries as a precious metal. The large-scale industrial production of silver-containing products and liquid waste emissions aggravate the environmental pollution. Silver ion is one of the most toxic metal ions, causing pollution to the environment and damage to public health. Therefore, the efficient and sensitive detection of Ag+in the water environment is extremely important. Sulfur-doped carbon nitride nanosheets (SCN Ns) were prepared by melamine and thiourea via high-temperature calcination. The morphology, chemical composition and surface functional groups of the SCN Ns were characterized by SEM, TEM, XRD, XPS, and FT-IR. The fluorescence of SCN Ns was gradually quenched as the Ag+concentration increased. The detection limit for Ag+was as low as 0.28 nM. The quenching mechanism mainly is attributed to static quenching. In this paper, SCN Ns were used as the fluorescent probe for detecting Ag+. SCN Ns have successfully detected Ag+in different environmental aqueous samples and cells. Finally, SCN Ns were further applied to the visual quantitative detection of intracellular Ag+.


Assuntos
Corantes Fluorescentes , Prata , Corantes Fluorescentes/química , Grafite , Íons , Compostos de Nitrogênio , Prata/química , Espectroscopia de Infravermelho com Transformada de Fourier , Enxofre
12.
J Colloid Interface Sci ; 608(Pt 1): 912-921, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34785466

RESUMO

Herein, we have assembled an anionic donor-acceptor (D-A) conjugated polyelectrolyte dots (Pdots), based on bithiophene units-containing backbone and sulfonate modified side chain (PCP-2F-Li), with porous g-C3N4 nanosheets (CNNS) into a new 0D/2D heterojunction (PCP-2F-Li Pdots/CNNS). The well-matched energy levels of PCP-2F-Li and CNNS and the strong electron-donating sulfinates in PCP-2F-Li can significantly accelerate the interfacial electron transfer in heterojunction, while the strong hydrophilicity of PCP-2F-Li can improve the interface wetting and promote the photocatalytic water-splitting. As such, PCP-2F-Li Pdots/CNNS can be used for efficient co-catalyst-free water splitting with a hydrogen evolution rate (HER) of 1932.1 µmol·h-1·g-1 over 6 runs, which is 1.85 and 2.29 times of hydrophobic F8T2 Pdots/CNNS and Pt-assisted CNNS, respectively. The apparent quantum yield (AQY) of PCP-2F-Li Pdots/CNNS can reach 7.87 %, 7.73 % and 5.60 % at 420, 450 and 475 nm, respectively. The findings highlight a new type of the Pdots-assisted heterojunctions for high-efficiency and durable co-catalyst-free water splitting.

13.
Talanta ; 230: 122311, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-33934776

RESUMO

Detection of anthrax biomarker dipicolinic acid (DPA) is of great importance upon the crisis of bioterrorism. Development of fluorescent materials for DPA detection, particularly one that fully depends on single luminescent response, faces the challenge of being susceptible to interferences. The accompanying accuracy problems offer great opportunities for the establishment of more reliable ratiometric analysis method. Herein, a ratiometric fluorescent probe based on terbium functionalized graphitic carbon nitride nanosheets (Tb-g-C3N4NS) is attempted for quantitative detection of DPA to address the distinct function of g-C3N4NS as both carrier and reference fluorophore, which is a so-far unexplored option in fluorescent detection approaches. We achieve the incorporation of Tb3+ into framework of g-C3N4NS by using a simple synthetic strategy comprised of thermal pyrolysis and ultrasonic exfoliation. Combining the reference signal over g-C3N4NS at 440 nm (I440) with the response signal of Tb3+ at 546 nm (I546), concentration of DPA can be easily calculated via its linear correlation with the intensity ratio (I546/I440), giving a precise measurement towards DPA with a detection limit as low as 9.9 nM. Besides enabling an excellent self-calibrating detection of DPA, this work also inspires broader use of g-C3N4NS for relevant process.


Assuntos
Antraz , Térbio , Antraz/diagnóstico , Biomarcadores , Fluorescência , Grafite , Humanos , Compostos de Nitrogênio
14.
J Colloid Interface Sci ; 601: 326-337, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34087593

RESUMO

The rapid recombination of photogenerated charges is one of the main restriction for promoting the photocatalytic H2 generation of graphitic carbon nitride (CN) material. Herein, donor-acceptor (D-A) system was introduced into CN nanosheets by oxygen and/or phenyl doping (DA-CN) strategy to facilitate the transport of photoinduced charge carriers and H2 generation. Experimental and theoretical results revealed that the nanosheet structure of DA-CN shortened the photoexcited charges transport length to the surface, and the D-A system embedded in DA-CN provided the dipole-induced internal electric field for charges transport. As a consequence, compared with pristine CN, DA-CN samples performed the improved transport of photogenerated charges and photocatalytic H2 evolution. Notably, DA-CN-OP (oxygen and phenyl co-doping) with the strongest dipole-induced internal electric field originated from D-A system displayed the highest photocatalytic H2 evolution rate at 7.394 mmol g-1h-1, which was 7.67 times as that of pristine CN (0.964 mmol g-1h-1). This work not only provides a simple strategy to construct highly efficient CN nanosheet photocatalyst with D-A system, but also promote the deep insight into the effect of molecular dipole originated from D-A system on the transport of photoinduced charge carriers and photocatalytic activity for CN material.

15.
J Colloid Interface Sci ; 598: 14-23, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-33887607

RESUMO

Graphitic carbon nitride (CN) generally needs to be exfoliated into ultrathin nanosheets to reduce photocarrier recombination. However, the exfoliation of CN into nanosheets also reduces the light absorption. How to simultaneously realize low photocarrier recombination and high light absorption remains a challenge in the practical application of CN in photocatalysis. Herein, the light absorption of CN nanosheets was enhanced by introducing hollow TiO2 (h-TiO2) dielectric resonators. The h-TiO2/CN heterostructures were prepared by thermally polymerizing dicyandiamide in the presence of h-TiO2. The electromagnetic resonances of the h-TiO2 resonator creates strong electric field enhancement within, inside, and near external surface of the introduced h-TiO2 nanoshells. The enhanced electric field greatly improves the light absorption of CN located in these regions. The largest hydrogen evolution rate for h-TiO2/CN can reach 6.3 mmol g-1h-1, which is over 3-fold that of pure CN (2.0 mmol g-1h-1). It is also found that the small amount of CN within and inside h-TiO2 majorly contributes to the photocatalytic performance. These findings open a new avenue by which to enhance the performance of photocatalysts and will be helpful in the design of highly efficient photocatalysts for various reactions.

16.
Food Chem ; 343: 128451, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33129619

RESUMO

In this work, fluorescent g-C3N4 NS with laminar morphology and ultrathin thickness were fabricated. The as synthesized NS were well characterized by UV-Visible and Fluorescence spectroscopy, FT-IR, XRD and HR-TEM. The bright blue fluorescent suspension of g-C3N4 NS was utilized for efficient detection of food colorant; tartrazine (Tz) and sunset yellow (SY). Both food colorant were able to quench fluorescence of NS efficiently were able to detect them selectively over other interfering analytes. The chemosensor showed linear range response for low concentration of Tz and SY with limit of detection for Tz and SY as 0.0325 µM (32.5 nM) and 0.221 µM (221 nM), respectively. They served as non-toxic and low cost photocatalyst. The catalytic degradation process was confirmed by mass and UV-Visible spectra analysis. The g-C3N4 NS served dual role of detection as well as photocatalytic degradation of food colorant.


Assuntos
Corantes de Alimentos/química , Grafite/química , Compostos de Nitrogênio/química , Espectrometria de Fluorescência , Catálise
17.
Talanta ; 219: 121235, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32887126

RESUMO

Herein, a novel ultrasensitive strategy has been developed by designing a label free fluorescent nano-aptasensor for monitoring of small moecules in human plasma. In this nano-aptasensor, graphitic carbon nitride nanosheets were used as fluorescent probe. The fluorescence intensity of the probe was decreased by interaction between graphitic carbon nitride nanosheets and label-free aptamer/gold nanoparticles conjugate, via Fluorescence resonance energy transfer mechanism. Upon addition of the analyte, the fluorescence of graphitic carbon nitride nanosheets was restored due to the aptamer/analyte interaction, and the aggregation of gold nanoparticles in the presence of salt. The influence of various factors on sensing method was investigated, and under the approved conditions, the fluorescence signal showed a linear relation with Digoxin concentration in the range of 10-500 ng L-1 with limit of detection down to 3.2 ng L-1 relative standard deviations for 25, 100 and 500 ng L-1 of analyte concentrations were 2.6, 4.0 and 6.5%, respectively. This strategy provided a simple, rapid, cost effective and reproducible experimental model, with successful application for determination of Digoxin in plasma samples without any pretreatment steps.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Nanopartículas Metálicas , Ouro , Grafite , Humanos , Nitrilas , Compostos de Nitrogênio
18.
J Biomed Mater Res B Appl Biomater ; 108(3): 1077-1084, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31389156

RESUMO

An oxidized, porous graphitic carbon nitride nanosheets (CNNs) was successfully obtained via a bottom-up approach. The inner filter effect (IFE) of Fe (III) tetrakis (1-methyl-4-pyridyl) porphyrin pentachlorideporphyrin pentachloride (FeTMPyP) on the CNNs results in fluorescence quenching of the CNNs due to the overlap of FeTMPyP absorbance band and CNNs emission band. It is interesting that the quenched fluorescence could be "turned on" in response to the participation of H2 O2 , which caused by decomposition of FeMPyP. In this study, for the first time, a porous fluorescence probe based on CNNs and FeTMPyP was designed and an excellent H2 O2 detection performance with a large detection range of 0.1 ~ 100 µM and a detection limit of 0.07 µM was achieved. Furthermore, the proposed method was successfully used for H2 O2 detection in RAW 264.7 cells.


Assuntos
Corantes Fluorescentes/química , Peróxido de Hidrogênio/química , Metaloporfirinas/química , Nanoestruturas/química , Oxigênio/química , Animais , Sobrevivência Celular , Grafite , Camundongos , Nanotecnologia/instrumentação , Compostos de Nitrogênio , Porosidade , Porfirinas/química , Células RAW 264.7 , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrometria de Fluorescência , Espectroscopia de Infravermelho com Transformada de Fourier , Ureia/química , Difração de Raios X
19.
Spectrochim Acta A Mol Biomol Spectrosc ; 230: 118040, 2020 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-31931354

RESUMO

A high-efficient chemiluminescence (CL) platform for highly selective and sensitive H2S detection was constructed on the basis of the quenching effect of S2- on the copper ion modified graphitic carbon nitride nanosheets (Cu2+-g-C3N4 NSs) enhanced luminol-H2O2 system. Cu2+-g-C3N4 NSs with horseradish peroxidase-like catalytic activity were prepared and provide a great improvement for luminol-H2O2 system. The presence of S2- induced the formation of CuS precipitate on g-C3N4 NSs surface. The precipitate can block the catalytic Cu2+ sites on the g-C3N4 NSs surface, resulting in a great CL decrease of CL system. Based on such a mechanism, a simple, highly selective and sensitive CL biosensor for H2S detection was designed. Under the optimized conditions, luminol-H2O2-Cu2+-g-C3N4 NSs system gave a decrease of CL intensity with the Na2S concentration increasing. The CL biosensor is in a linear range of 10.0 pM-50.0 nM and the detection limit for detecting Na2S is as low as 2.0 pM. Moreover, the method here has enjoyed a successful application for determining H2S in human plasma samples and the recovery is between 95.7% and 110.0%.


Assuntos
Grafite/química , Sulfeto de Hidrogênio/sangue , Substâncias Luminescentes/química , Luminol/química , Nanoestruturas/química , Compostos de Nitrogênio/química , Técnicas Biossensoriais/métodos , Humanos , Peróxido de Hidrogênio/química , Limite de Detecção , Luminescência , Medições Luminescentes/métodos
20.
J Colloid Interface Sci ; 533: 144-153, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30149223

RESUMO

Great advances in photocatalysis have been made by developing various efficient photocatalysts, but investigation on practical applications of photocatalysis is relatively backward. Herein we report a facile surface modification approach to functionalize textiles with excellent ability for photocatalytic self-cleaning and degradation of indoor volatile organic pollutants. Graphitic carbon nitride nanosheets (CNNS) in colloidal suspension were directly sprayed onto the surface of cellulose fibers in textiles, and the powerful hydrogen bonding action between surface hydroxyl groups of cellulose and plentiful hydroxyl and amino groups of exfoliated CNNS from alkali-treating realizes high stability of CNNS modified textiles. Due to ultrathin 2D thickness and high visible light transparency, the modification of CNNS would not affect the hand feeling of textiles and shield their original colors. The obtained textiles show superior photocatalytic self-cleaning performance to remove stains from various colored pollutants under solar light irradiation, including industrial organic dyes and juices. Meanwhile, gaseous formaldehyde also can be efficiently decomposed using Xe lamp or commercial LED lamp as light sources. This work realizes photocatalytic performance of textiles using a simple spraying method, and it has great potential application in textile self-cleaning, not only for surface stains but also for volatile organic compounds from textile release.

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