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1.
Polymers (Basel) ; 16(11)2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38891556

RESUMO

It is well-established that the structural, morphological and performance characteristics of nanoscale materials critically depend upon the dispersion state of the nanofillers that is, in turn, largely determined by the preparation protocol. In this report, we review synthetic strategies that capitalise on the in situ generation of nanoparticles on and within polymeric materials, an approach that relies on the chemical transformation of suitable precursors to functional nanoparticles synchronous with the build-up of the nanohybrid systems. This approach is distinctively different compared to standard preparation methods that exploit the dispersion of preformed nanoparticles within the macromolecular host and presents advantages in terms of time and cost effectiveness, environmental friendliness and the uniformity of the resulting composites. Notably, the in situ-generated nanoparticles tend to nucleate and grow on the active sites of the macromolecular chains, showing strong adhesion on the polymeric host. So far, this strategy has been explored in fabrics and membranes comprising metallic nanoparticles (silver, gold, platinum, copper, etc.) in relation to their antimicrobial and antifouling applications, while proof-of-concept demonstrations for carbon- and silica-based nanoparticles as well as titanium oxide-, layered double hydroxide-, hectorite-, lignin- and hydroxyapatite-based nanocomposites have been reported. The nanocomposites thus prepared are ideal candidates for a broad spectrum of applications such as water purification, environmental remediation, antimicrobial treatment, mechanical reinforcement, optical devices, etc.

2.
Talanta ; 278: 126446, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38936107

RESUMO

The simultaneous synthesis of gold nanoparticles (AuNPs) and graphene by laser ablation was demonstrated. The in-situ synthesis was performed by laser ablation of a polymer substrate covered with a gold precursor dispersion. The gold precursor was prepared in a copolymer solution of pyrrole (Py) and chitosan (Chi) to improve the nucleation of gold embedded on the laser-induced graphene electrode (LIGE). The morphology of AuNPs-pPy-Chi/LIGE was studied by scanning electron microscopy and characterized electrochemically by cyclic voltammetry. A comprehensive investigation of the electrochemical and physical features of the AuNPs-pPy-Chi/LIGE was carried out. The parameters of differential pulse voltammetry were adjusted to enhance the response to ascorbic acid (AA). The AuNPs-pPy-Chi/LIGE produced two linear ranges: from 0.25 to 5.00 and 5.00-25.00 mmol L-1. The limit of detection was 0.22 mmol L-1. Hundreds of electrodes were tested to demonstrate the excellent reproducibility of the AuNPs-pPy-Chi/LIGE fabrication. Overall, the proposed electrode allows the successful detection of AA in orange juice products with acceptable accuracy (recoveries = 97 ± 2 to 109.1 ± 0.7). The preparation strategy of the proposed AuNPs-pPy-Chi/LIGE could be adapted to detect other compounds or biomarkers.

3.
Food Res Int ; 186: 114340, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38729695

RESUMO

Fruits are essential sources of nutrients in our daily diet; however, their spoilage is often intensified by mechanical damage and the ethylene phytohormone, resulting in significant economic losses and exacerbating hunger issues. To address these challenges, this study presented a straightforward in situ synthesis protocol for producing Z/SOPPU foam, a 3D porous-structured fruit packaging. This innovative packaging material offered advanced ethylene-adsorbing and cushioning capabilities achieved through stirring, heating, and standing treatments. The results demonstrated that the Z/SOPPU foam, with its porous structure, served as an excellent packaging material for fruits, maintaining the intact appearance of tomatoes even after being thrown 72 times from a height of 1.5 m. Additionally, it exhibited desirable hydrophobicity (contact angle of 114.31 ± 0.82°), degradability (2.73 ± 0.88 % per 4 weeks), and efficient ethylene adsorption (adsorption rate of 13.2 ± 1.7 mg/m3/h). These remarkable characteristics could be attributed to the unique 3D micron-porous configuration, consisting of soybean oil polyol polyurethane foam for mechanical strain cushioning and zein for enhanced ethylene adsorption efficiency. Overall, this research offers an effective and original approach to the rational design and fabrication of advanced bio-based fruit packaging.


Assuntos
Etilenos , Embalagem de Alimentos , Frutas , Poliuretanos , Óleo de Soja , Zeína , Etilenos/química , Poliuretanos/química , Embalagem de Alimentos/métodos , Porosidade , Frutas/química , Óleo de Soja/química , Zeína/química , Adsorção , Polímeros/química , Solanum lycopersicum/química , Interações Hidrofóbicas e Hidrofílicas
4.
Small ; : e2401308, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38773889

RESUMO

Incorporating ultralow loading of nanoparticles into polymers has realized increases in dielectric constant and breakdown strength for excellent energy storage. However, there are still a series of tough issues to be dealt with, such as organic solvent uses, which face enormous challenges in scalable preparation. Here, a new strategy of dual in situ synthesis is proposed, namely polymerization of polyethylene terephthalate (PET) synchronizes with growth of calcium borate nanoparticles, making polyester nanocomposites from monomers directly. Importantly, this route is free of organic solvents and surface modification of nanoparticles, which is readily accessible to scalable synthesis of polyester nanocomposites. Meanwhile, uniform dispersion of as ultralow as 0.1 wt% nanoparticles and intense bonding at interfaces have been observed. Furthermore, the PET-based nanocomposite displays obvious increases in both dielectric constant and breakdown strength as compared to the neat PET. Its maximum discharged energy density reaches 15 J cm-3 at 690 MV m-1 and power density attains 218 MW cm-3 under 150 Ω resistance at 300 MV m-1, which is far superior to the current dielectric polymers that can be produced at large scales. This work presents a scalable, safe, low-cost, and environment-friendly route toward polymer nanocomposites with superior capacitive performance.

5.
Sci Rep ; 14(1): 11652, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38773210

RESUMO

This project investigated the impact of low-temperature, in-situ synthesis of cerium oxide (CeO2) nanoparticles on various aspects of oil recovery mechanisms, including changes in oil viscosity, alterations in reservoir rock wettability, and the resulting oil recovery factor. The nanoparticles were synthesized using a microemulsion procedure and subjected to various characterization analyses. Subsequently, these synthesized nanoparticles were prepared and injected into a glass micromodel, both in-situ and ex-situ, to evaluate their effectiveness. The study also examined the movement of the injected fluid within the porous media. The results revealed that the synthesized CeO2 nanoparticles exhibited a remarkable capability at low temperatures to reduce crude oil viscosity by 28% and to lighten the oil. Furthermore, the addition of CeO2 nanoparticles to the base fluid (water) led to a shift in the wettability of the porous medium, resulting in a significant reduction in the oil drop angle from 140° to 20°. Even a minimal presence of CeO2 nanoparticles (0.1 wt%) in water increased the oil production factor from 29 to 42%. This enhancement became even more pronounced at a concentration of 0.5 wt%, where the oil production factor reached 56%. Finally, it was found that the in-situ injection, involving the direct synthesis of CeO2 nanoparticles within the reservoir using precursor salts solution and reservoir energy, led to an 11% enhancement in oil production efficiency compared to the ex-situ injection scenario, where the nanofluid is prepared outside the reservoir and then injected into it.

6.
ACS Appl Bio Mater ; 7(5): 3414-3430, 2024 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-38687465

RESUMO

We have semi-synthesized a natural product 7-acetylhorminone from crude extract of Premna obtusifolia (Indian headache tree), which is active against colorectal cancer after probation through computational screening methods as it passed through the set parameters of pharmacokinetics (most important nonblood-brain barrier permeant) and drug likeliness (e.g., Lipinski's, Ghose's, Veber's rule) which most other phytoconstituents failed to pass combined with docking with EGFR protein which is highly upregulated in the colorectal carcinoma cell. The structure of 7-acetylhorminone was confirmed by single crystal X-ray diffraction studies and 1H NMR, 13C NMR, and COSY studies. To validate the theoretical studies, first, in vitro experiments were carried out against human colorectal carcinoma cell lines (HCT116) which revealed the potent cytotoxic efficacy of 7-acetylhorminone and verified preliminary investigation. Second, the drugability of 7-acetylhorminone interaction with serum albumin proteins (HSA and BSA) is evaluated both theoretically and experimentally via steady-state fluorescence spectroscopic studies, circular dichroism, isothermal titration calorimetry, and molecular docking. In summary, this study reveals the applicability of 7-acetylhorminone as a potent drug candidate or as a combinatorial drug against colorectal cancer.


Assuntos
Neoplasias Colorretais , Soroalbumina Bovina , Humanos , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Soroalbumina Bovina/metabolismo , Soroalbumina Bovina/química , Ensaios de Seleção de Medicamentos Antitumorais , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Estrutura Molecular , Teste de Materiais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Antineoplásicos/farmacologia , Antineoplásicos/química , Células HCT116 , Proliferação de Células/efeitos dos fármacos , Simulação de Acoplamento Molecular , Sobrevivência Celular/efeitos dos fármacos , Albumina Sérica Humana/química , Albumina Sérica Humana/metabolismo
7.
Polymers (Basel) ; 16(8)2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38675044

RESUMO

The addition of nanostructures to polymeric materials allows for a direct interaction between polymeric chains and nanometric structures, resulting in a synergistic process through the physical (electrostatic forces) and chemical properties (bond formation) of constituents for the modification of their properties and potential cutting-edge materials. This study explores a novel in situ synthesis method for PDMS-%SiO2 nanoparticle composites with varying crosslinking degrees (PDMS:TEOS of 15:1, 10:1, and 5:1); particle concentrations (5%, 10%, and 15%); and sol-gel catalysts (acidic and alkaline). This investigation delves into the distinct physical and chemical properties of silicon nanoparticles synthesized under acidic (SiO2-a) and alkaline (SiO2-b) conditions. A characterization through Raman, FT-IR, and XPS analyses confirms particle size and agglomeration differences between both the SiO2-a and SiO2-b particles. Similar chemical environments, with TEOS and ethanol by-products, were detected for both systems. The results on polymer composites elucidate the successful incorporation of SiO2 nanoparticles into the PDMS matrix without altering the PDMS's chemical structure. However, the presence of nanoparticles did affect the relative intensities of specific vibrational modes over composites from -35% to 24% (Raman) and from -14% to 59% (FT-IR). The XPS results validate the presence of Si, O, and C in all composites, with significant variations in atomic proportions (C/Si and O/Si) and Si and C component analyses through deconvolution techniques. This study demonstrates the successful in situ synthesis of PDMS-SiO2 composites with tunable properties by controlling the sol-gel and crosslinking synthesis parameters. The findings provide valuable insights into the in situ synthesis methods of polymeric composite materials and their potential integration with polymer nanocomposite processing techniques.

8.
J Chromatogr A ; 1724: 464924, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38653038

RESUMO

This work, reports the successful preparation a thin film by a simple and inexpensive process for quantification of a model analytes in the urine sample using HPLC-UV. To this end, cellulose paper was employed as a substrate for the in-situ synthesis of MOF-5, to increase the resistance of the prepared film. The prepared film can be reused 26 times with no reduction in its performance. The thin film prepared by MOF-5 modified cellulose substrate was utilized in thin film microextraction (TFME) method for the extraction and preconcentration of naproxen, aspirin, tolmetin, and celecoxib. Under optimal conditions, the linear dynamic range of the target analytes was 2-500 µg L-1 with correlation coefficients (R2) ranging from 0.9961 to 0.9990. Also, the limits of detection (LODs), the limits of quantification (LOQs) and relative standard deviation (RSD%) of the proposed method for selected analytes ranged between 0.57 and 0.77 µg L-1, 1.7 to 2.3 and 3.5 % to 6.2 %, respectively. Moreover, relative recoveries varied from of 94 % to 108 %, indicating the absence of matrices effect in the proposed method. Eventually, the TFME was successfully used for the extraction of selected analytes from urine samples.


Assuntos
Anti-Inflamatórios não Esteroides , Celulose , Limite de Detecção , Estruturas Metalorgânicas , Microextração em Fase Sólida , Cromatografia Líquida de Alta Pressão/métodos , Celulose/química , Estruturas Metalorgânicas/química , Humanos , Anti-Inflamatórios não Esteroides/urina , Anti-Inflamatórios não Esteroides/análise , Anti-Inflamatórios não Esteroides/isolamento & purificação , Microextração em Fase Sólida/métodos , Reprodutibilidade dos Testes
9.
ACS Appl Mater Interfaces ; 16(12): 15617-15631, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38486478

RESUMO

The inkjet printing is a simple method to develop pattern-controlled 2D metal-organic frameworks (MOFs) due to its cost-effectiveness and ease of operation. Despite the sophisticated structures of MOF crystals, the MOF surfaces are easily contaminated by the adsorption of an ink solution, and the printing nozzle can be clogged by the aggregates of MOFs during printing. Unlike the mixture inks of MOFs and a carrier medium, the surface-specific patterning by in situ synthesis provides the film surface with the controlled patterns of an MOF single layer having different morphologies of MOFs without changing the ink cartridges. It enables facile printing due to the low viscosity of inks and escapes the risk of nozzle clogging because MOFs are synthesized at the printed patterns on the substrates. The ion-exchanged cellulose nanofiber (CNF) films form strong coordination with metal ions enhancing the stability of the MOFs on the film surface. It also demonstrates the controlled coverage of the MOFs by the printing pass number and the carboxylate content of CNF and the tunable adsorption of the guest molecules for different loading capacities of the printed patterns.

10.
Anal Chim Acta ; 1292: 342211, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38309843

RESUMO

Radioactive uranium leaks into natural water bodies mainly in the form of uranyl ions (UO22+), posing ecological and human health risks. Fluorescent europium-based metal-organic frameworks (Eu-MOFs) have been demonstrated to be effective fluorescent sensors for UO22+, but the large size, powder state and poor dispersity limit their further application. In this work, fluorescent Eu-MOFs were in-situ grown on TEMPO-oxidized cellulose nanofibers (TOCNFs), which is the first time that spherical Eu-MOF crystals with sizes below 10 nm were prepared. Fluorescence spectral analysis revealed a nine-fold increase in the fluorescence intensity of TOCNF@Eu-MOF compared to Eu-MOF. The nanocomposites achieved rapid and sensitive fluorescence quenching to UO22+ through the "antenna effect" and unsaturated Lewis basic sites on the ligands binding with UO22+. Moreover, TOCNF@Eu-MOF demonstrated excellent selectivity and anti-interference for UO22+ detection. For the nanopaper-based sensor made from TOCNF@Eu-MOF, the Stern-Volmer quenching constant (KSV) was calculated as 8.21 × 104 M-1, and the lowest limit of detection (LOD) was 6.6 × 10-7 M, significantly lower than the 1.32 × 10-6 M of Eu-MOFs. In addition, the nanopaper exhibited good fluorescence stability and cyclic detection performance, enabling the rapid and convenient detection of UO22+ in the aqueous phase within 30 s by simple dipping.

11.
Angew Chem Int Ed Engl ; 63(18): e202402397, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38389036

RESUMO

Single-atom nanozyme (SAzyme) has sparked increasing interest for catalytic antitumor treatment due to their more tunable and diverse active sites than natural metalloenzymes in complex physiological conditions. However, it is usually a hard task to precisely conduct catalysis at tumor sites after intravenous injection of those SAzyme with high reactivity. Moreover, the explorations of SAzymes in the anticancer application are still in its infancy and need to be developed. Herein, an in situ synthesis strategy for Cu SAzyme was constructed to convert adsorbed copper ions into isolated atoms anchored by oxygen atoms (Cu-O2/Cu-O4) via GSH-responsive deformability of supports. Our results suggest that the in situ activation process could further facilitate the dissociation of copper ions and the consumption of glutathione, thereby leading to copper deposition in cytoplasm and triggering cuproptosis. Moreover, the in situ synthesis of Cu SAzyme with peroxidase-like activity enabled the intracellular reactive oxygen species production, resulting in specifically disturbance of copper metabolism pathway. Meanwhile, the in situ exposed glucose transporter (GLUT) inhibitor phloretin (Ph) can block the glycose uptake to boost cuproptosis efficacy. Overall, this in situ activation strategy effectively diminished the off-target effects of SACs-induced catalytic therapies and introduced a promising treatment paradigm for advancing cuproptosis-associated therapies.


Assuntos
Cobre , Glutationa , Anaerobiose , Catálise , Glicólise , Oxigênio , Íons
12.
J Mech Behav Biomed Mater ; 151: 106383, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38218046

RESUMO

Bone transplantation is the second most common transplantation surgery in the world. Therefore, there is an urgent need for artificial bone transplantation to repair bone defects. In bone tissue engineering, hydroxyapatite (HA) plays a major role in bone graft applications. This study deals with a facile method for synthesizing HA hexagonal nanorods from seashells by a solid-state hydrothermal transition process. The synthesized HA nanorods (∼2.29 nm) were reinforced with carbon nanotube and chitosan on graphene oxide sheets with polymeric support by in-situ synthetic approach. Among the synthesized nanocomposites viz., hydroxyapatite-graphene oxide (HA-GO), hydroxyapatite-graphene oxide-chitosan (HA-GO-CS), hydroxyapatite-graphene oxide-chitosan-carbon nanotube-polylactic acid (HA-GO-CS-CNT-PLA). Among them, the HA-GO-CS-CNT-PLA composite exhibits micro and macro porosity (∼200 to 600 µm), higher mechanical strength, (Hardness ∼90.5 ± 1.33 MPa; Tensile strength 25.62 MPa), and maximum cell viability in MG63 osteoblast-like cells (80%). The self-assembled hybrid-nanocomposite of HA-GO-CS-CNT-PLA is a promising material for bone filler application and could efficiently utilize seashell waste through the green process.


Assuntos
Quitosana , Grafite , Nanocompostos , Nanotubos de Carbono , Animais , Durapatita , Exoesqueleto , Medicina Regenerativa , Engenharia Tecidual , Poliésteres , Alicerces Teciduais
13.
Materials (Basel) ; 17(2)2024 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-38255572

RESUMO

Nowadays, due to the increasing number of diseases and injuries related to bone tissue, there is an acute problem of creating a material that could be incorporated into the bone tissue structure and contribute to accelerated bone regeneration. Such materials can be represented by a polymeric matrix that holds the material in the bone and an inorganic component that can be incorporated into the bone structure and promote accelerated bone regeneration. Therefore, in this work we investigated polyvinyl alcohol-based composite cryogels containing an in situ deposited inorganic filler, hydroxyapatite. The freezing temperature was varied during the synthesis process. The composition of the components was determined by infrared spectroscopy and the phase composition by X-ray phase analysis, from which it was found that the main phase of the composite is hydroxyapatite and that the particle size decreases with increasing freezing temperature. The elemental composition of the surface is dominated by carbon, oxygen, phosphorus and calcium; no impurities of other elements not typical for polyvinyl alcohol/ hydroxyapatite cryogels were found. Higher mechanical properties and melting points were observed at -15 °C. Cryogenic treatment parameters did not affect cell viability; however, cell viability was above 80% in all samples.

14.
Small ; 20(12): e2307259, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37948421

RESUMO

As one of the important directions of solar energy utilization, the construction of composite photothermal phase change materials (PCM) with reasonable network support and low leakage in the simple method is important to solve the transient availability of solar energy and achieve long-lasting energy output. Here, a multifunctional silylated bacterial cellulose (BC)/hydroxylated carbon nanotube (HCNT)/polyethylene glycol (PEG) (SBTP) photothermal film-based PCM with cross-linked network structure is prepared by simple one-step synthesis. The formation of the cross-linked network structure achieves the enhancement of BC support network, prominent dispersion of HCNT and the direct introduction and perfect interlocking of PEG. Therefore, the optimal SBTP film exhibits high thermal enthalpy of 145.1 J g-1, enthalpy efficiency of over 94%, robust shape stability and low leakage of <1.2%. It also displays high photothermal conversion of over 80 °C, photothermal storage of 394 s g-1 and excellent stability. Thus, it can demonstrate a maximum output voltage of 423 mV and high power density of 30.26 W m-2 under three solar irradiations when applied in the solar-thermal-electric energy conversion field. Meanwhile, it also can apply in the thermal management of solar cell and light-emitting diode (LED) chip, and convert the waste heat into electricity, demonstrating multi-scene application capability.

15.
Bioelectrochemistry ; 156: 108627, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38142545

RESUMO

The level of folate receptor (FR) has become one of the independent factors for measuring human tumor diseases. The precise quantification of FR is helpful for the early diagnosis and subsequent treatment of tumors. The modification of electrodes is a key issue in ensuring and enhancing the electrochemical biosensing ability. In this study, we in-situ synthesized a nanocomposite material with excellent conductivity and stability by grafting first-generation poly(amidoamine) dendrimers onto the MXene (Ti3C2TX) as the immobilized matrix (PAMAM@MXene). An electrochemical sensor was developed for FR monitor by loading the PAMAM@MXene on screen-printed carbon electrodes (SPCEs). Scanning electron microscopy (SEM) supported the effective synthesis of PAMAM@MXene. Under optimal conditions, the prepared sensor achieved the quantification of FR with a wide range of concentrations from 10 ng/mL to 1000 ng/mL with a detection limit (LOD) of 5.6 ng/mL. It also exhibited satisfactory selectivity, reproducibility, and stability, which provided the possibility for expanding new pathways in the detection of clinical FR.


Assuntos
Técnicas Biossensoriais , Neoplasias , Nitritos , Elementos de Transição , Humanos , Reprodutibilidade dos Testes , Técnicas Eletroquímicas , Eletrodos , Ácido Fólico
16.
J Colloid Interface Sci ; 656: 513-527, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38007943

RESUMO

Generally, the transport of electrons and Na+ is seriously constrained in Na3V2(PO4)3 (NVP) due to intense interactions of V-O and PO bonds. Besides, polyamide acid (PAA) is hardly used in the sol-gel route due to insolubility. This work develops a facile liquid synthesis strategy based on modified PAA, achieving in-situ construction of a porous N-doped carbon framework with rich defects to improve the kinetics of NVP. The addition of triethylamine (TEA) reacts with carboxyls in PAA to achieve acid-base neutralization, turning PAA into polyamide salts with good solubility. The special morphology construction mechanism of this unique system was observed by ex-situ scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). Specifically, PAA undergoes in-situ conversion into chain-like polyimide (PI) through a thermal polymerization mechanism during the pre-sintering process. Meanwhile, NVP precursors are evenly dispersed in the PI fibers, efficiently reducing the particle size. After the final treatment, the favorable porous carbon skeleton could be generated derived from the partial decomposition of PI, on which small active grains are in situ grown. The resulting N-doped carbon substrate contains rich defects, benefiting from the migration of Na+. Furthermore, the porous construction is conducive to alleviating the stress and strain generated by the high current impact, increasing the contact area between electrodes/electrolytes to improve the utilization efficiency of active substances. Comprehensively, the optimized samples exhibit a capacity of 82.1 mAh g-1 at 15C with a retention rate of 95.45 % after 350 cycles. It submits a capacity of 67.6 mAh g-1 at 90C and remains 52.2 mAh g-1 after 1500 cycles. Even in full cells, it reveals a value of 110.6 mAh g-1. This work guides the application of in-situ multiple modifications of polymers in electrode materials.

17.
Talanta ; 270: 125550, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38104426

RESUMO

Developing ultrasensitive sensing platforms for trace ochratoxin A (OTA) in food safety is still challenging. Herein, we presented a novel dual-mode sensing strategy for fluorescence and colorimetric detection of OTA by combining the target-responsive hemin-encapsulated and copper nanoclusters (CuNCs) functionalized DNA hydrogel. Through simple assembly and in situ synthesis methods, fluorescence CuNCs are synthesized and modified on the 3D hydrophilic network structure of DNA cross-linked. OTA specifically recognized by Apt-linker can control the collapse of hydrogel, resulting in the fluorescence quenching of CuNCs and release of coated hemin. Interestingly, OTA could trigger Apt-linker conformational changes to form G-quadruplex structures, allowing the released hemin to form G-quadruplex/hemin DNAzyme via self-assembly. Fluorescence signal amplification could be achieved through further fluorescence quenching of CuNCs caused by DNAzyme-catalyzed hydrogen peroxide (H2O2) because of the peroxidase activity of DNAzyme. Simultaneously, DNAzyme could catalyze the H2O2-mediated oxidation of TMB to provide colorimetric signal. Thereafter, the DNA-CuNCs hydrogel exhibited low detection limits of 3.49 pg/mL in fluorescence mode and 0.25 ng/mL in colorimetric modality. Real sample analyses of foodstuffs showed satisfactory results, providing prospective potential for monitoring mycotoxin contaminant.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , DNA Catalítico , Quadruplex G , Ocratoxinas , DNA Catalítico/química , Cobre , Hidrogéis , Hemina/química , Peróxido de Hidrogênio/química , DNA , Técnicas Biossensoriais/métodos , Limite de Detecção , Aptâmeros de Nucleotídeos/química
18.
Curr Issues Mol Biol ; 45(12): 9943-9960, 2023 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-38132467

RESUMO

Enhanced ultraviolet-B (UV-B) radiation promotes anthocyanin biosynthesis in leaves, flowers and fruits of plants. However, the effects and underlying mechanisms of enhanced UV-B radiation on the accumulation of anthocyanins in the tubers of potatoes (Solanum tuberosum L.) remain unclear. Herein, reciprocal grafting experiments were first conducted using colored and uncolored potatoes, demonstrating that the anthocyanins in potato tubers were synthesized in situ, and not transported from the leaves to the tubers. Furthermore, the enhanced UV-B radiation (2.5 kJ·m-2·d-1) on potato stems and leaves significantly increased the contents of total anthocyanin and monomeric pelargonidin and peonidin in the red-fleshed potato '21-1' tubers, compared to the untreated control. A comparative transcriptomic analysis showed that there were 2139 differentially expressed genes (DEGs) under UV-B treatment in comparison to the control, including 1724 up-regulated and 415 down-regulated genes. The anthocyanin-related enzymatic genes in the tubers such as PAL, C4H, 4CL, CHS, CHI, F3H, F3'5'H, ANS, UFGTs, and GSTs were up-regulated under UV-B treatment, except for a down-regulated F3'H. A known anthocyanin-related transcription factor StbHLH1 also showed a significantly higher expression level under UV-B treatment. Moreover, six differentially expressed MYB transcription factors were remarkably correlated to almost all anthocyanin-related enzymatic genes. Additionally, a DEGs enrichment analysis suggested that jasmonic acid might be a potential UV-B signaling molecule involved in the UV-B-induced tuber biosynthesis of anthocyanin. These results indicated that enhanced UV-B radiation in potato stems and leaves induced anthocyanin accumulation in the tubers by regulating the enzymatic genes and transcription factors involved in anthocyanin biosynthesis. This study provides novel insights into the mechanisms of enhanced UV-B radiation that regulate the anthocyanin biosynthesis in potato tubers.

19.
Int J Biol Macromol ; 253(Pt 7): 127259, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37802436

RESUMO

Developing an environment-friendly preparation method for silver nanoparticles (AgNPs) composite is significant. However, it remains challenges in size adjustment and content improvement of AgNPs. Here, the NaIO4 oxidation and TEMPO-mediated oxidation were applied to bagasse pulp to prepare nanocellulose (NC) with both carboxyl and aldehyde groups. The aldehyde content of NC could be adjusted in the range of 0.21-1.45 mmol/g by different NaIO4 oxidation times. When the carboxyl groups were protonated, NC with a high length-diameter ratio could construct stable hydrogels in a low concentration at 0.5 wt%. The NC hydrogels showed excellent in situ synthesis ability of AgNPs with abundant pore structure. By regulating the carboxyl group content of NC, the size distribution of synthesized AgNPs could be controlled in the range of 7.14-28.6 nm with high content of 6.79-11.0 %. The NC/AgNPs composite hydrogel exhibited high catalytic degradation activity for 4-nitrophenol and antibacterial activity. This approach for constructing NC hydrogel paves the way for AgNPs composite products with adjustable sizes and high contents.


Assuntos
Nanopartículas Metálicas , Nanopartículas Metálicas/química , Prata/química , Hidrogéis/química , Antibacterianos/farmacologia , Antibacterianos/química , Aldeídos
20.
Nanomaterials (Basel) ; 13(17)2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37686961

RESUMO

Photocatalytic hydrogen production is a promising technology that can generate renewable energy. However, light absorption and fast electron transfer are two main challenges that restrict the practical application of photocatalysis. Moreover, most of the composite photocatalysts that possess better photocatalytic performance are fabricated by various methods, many of which are complicated and in which, the key conditions are hard to control. Herein, we developed a simple method to prepare CdS/Cd(OH)2 samples via an in situ synthesis approach during the photocatalytic reaction process. The optimal hydrogen generation rate of CdS/Cd(OH)2 that could be obtained was 15.2 mmol·h-1·g-1, greater than that of CdS, which generates 2.6 mmol·h-1·g-1 under visible light irradiation. Meanwhile, the CdS-3 sample shows superior HER performance during recycling tests and exhibits relatively steady photocatalytic performance in the 10 h experiment. Expanded absorption of visible light, decreased recombination possibility for photo-induced carriers and a more negative conduction band position are mainly responsible for the enhanced photocatalytic hydrogen evolution performance. Photo-induced electrons will be motivated to the conduction band of CdS under the irradiation of visible light and will further transfer to Cd(OH)2 to react with H+ to produce H2. The in situ-formed Cd(OH)2 could effectively facilitate the electron transfer and reduce the recombination possibility of photo-generated electron-hole pairs.

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