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1.
Dalton Trans ; 52(4): 1052-1061, 2023 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-36602082

RESUMO

The spectrum and size controllable synthesis of gold nanorods is of great value for their widely applicable aspect ratio dependence of anisotropic surface plasmon resonance. Herein, 1,7-dihydroxynaphthalene with a relatively strong reducibility is proposed as a reducing agent for the controllable synthesis of gold nanorods. The result indicated that gold nanorods with high monodispersity, high shape yield, relatively small diameters, and maximum plasmon resonance wavelength of above 1000 nm can be acquired. More importantly, by virtue of the reducing agent used, fine and precise controls over the plasmon wavelength and diameter of the rod can be achieved via changes in experimental conditions. In particular, increases in the concentration of both silver ions and cetyltrimethylammonium bromide (CTAB) can increase the plasmon wavelength from around 600 nm to 1000 nm but respectively show a decreased diameter with the smallest value of around 14.3 nm and a mildly increased diameter from around 9.0 nm to 14.3 nm; moreover, increasing the concentration of reducing agents and gold seeds can simultaneously cause decreases in the plasmon wavelength from around 1000 nm to 800 nm and the diameters from around 14.3 nm to 9.0 and 7.3 nm, respectively. This powerful and efficient method of controllable synthesis of AuNRs could be valuable and attractive for the application of the as-obtained particles.


Assuntos
Nanotubos , Substâncias Redutoras , Ouro , Cetrimônio , Compostos de Cetrimônio
2.
Chempluschem ; 88(1): e202200416, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36680307

RESUMO

Green hydrogen, using sustainable energy to decompose water to produce hydrogen, is regarded as the ideal and effective connection to convert electricity into chemical energy. Herein, well designed Ni-doped Mo2 C nanorod electrodes self-supported on three types of substrates (Ni foam, Cu foam and stainless steel wire mesh) with outstanding gas resistance and prominent corrosion resistance were assembled together to build up a wide pH applicable electrode for Hydrogen Evolution. In particular, Ni-doped Mo2 C nanorod arrays on stainless steel wire mesh donated as Ni-Mo2 C@SSW exhibited remarkable electrocatalytic properties towards hydrogen evolution reaction with superior overpotentials both in 1 M KOH and 0.5 M H2 SO4 (102 mV and 106 mV at the current density of 10 mA cm-2 ) and incomparable continuous durability. This work provides the possibility for the realization of low cost, high activity and ultra-stable durability HER electrocatalysts in practical industrial application.


Assuntos
Nanotubos , Níquel , Aço Inoxidável , Hidrogênio , Concentração de Íons de Hidrogênio
3.
Molecules ; 28(1)2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36615591

RESUMO

Zinc oxide nanorods were grown on an aluminum-doped zinc oxide seeds layer using the chemical bath deposition method. The effects of growth reaction time on the structural, optical, and photocatalytic properties of zinc oxide nanorods were investigated. It was clearly observed that the growth direction of zinc oxide nanorods were dependent on the crystallinity of the as-deposited aluminum-doped zinc oxide seed layer. The crystallinity of the obtained zinc oxide nanorods was improved with the increase in reaction times during the chemical bath deposition process. The mechanism of zinc oxide nanorod growth revealed that the growth rate of nanorods was influenced by the reaction times. With increasing reaction times, there were much more formed zinc oxide crystalline stacked growth along the c-axis orientation resulting in an increase in the length of nanorods. The longest nanorods and the high crystallinity were obtained from the zinc oxide nanorods grown within 5 h. The optical transmittance of all zinc oxide nanorods was greater than 70% in the visible region. Zinc oxide nanorods grown for 5 h showed the highest degradation efficiency of methyl red under ultraviolet light and had a high first-order degradation rate of 0.0051 min-1. The photocatalytic mechanism was revealed as well.


Assuntos
Nanotubos , Óxido de Zinco , Óxido de Zinco/química , Tempo de Reação , Alumínio , Nanotubos/química , Raios Ultravioleta
4.
Biosens Bioelectron ; 223: 115038, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36587445

RESUMO

As one of the most toxic chemical substances, aflatoxin B1 (AFB1) has a strong carcinogenic effect even at a trace level in human and animal, which severely threatens human health and even causes cancers. Therefore, ultrasensitive detection of AFB1 is of significant importance. For such analysis, dual II-scheme sheet-like Bi2S3/Bi2O3/Ag2S heterostructures were prepared by the in-situ growth method, which exhibited high separation efficiency for the electron-hole (e--h+) pairs, prominent stability, and high photoactivity. Moreover, the dendritic nanorod-like Au@Pd@Pt (Au@Pd@Pt DNRs) nanozyme was homely synthesized, whose peroxidase-like activity was scrupulously investigated by catalytical oxidation of diaminobenzidine (DAB) in the presence of H2O2. Integration by the aptasensing strategy, a photoelectrochemical (PEC) "signal-on" aptasensor was prepared, which exhibited a broader linear range of 0.5 pg mL-1-100 ng mL-1 with a lower limit of detection (LOD = 0.09 pg mL-1, S/N = 3). This work provides a feasible strategy to develop advanced PEC biosensors for actual analysis of environmental pollutants.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Nanotubos , Animais , Humanos , Técnicas Biossensoriais/métodos , Aflatoxina B1/análise , Peróxido de Hidrogênio , Aptâmeros de Nucleotídeos/química , Técnicas Eletroquímicas/métodos , Limite de Detecção , Nanotubos/química
5.
Biosensors (Basel) ; 13(1)2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36671923

RESUMO

Herein, the detection of aspartic acid by doped Co3O4-ZnO nanorod materials was proposed using differential pulse voltammetry. The nano-composite metal oxide was synthesized by the wet precipitation method in basic media. Aspartic acid is a non-essential amino acid naturally synthesized in the body with lot of health significance, including as a biomarker for several health deficiencies. The synthesized composite Co3O4-ZnO nanorod was well-investigated by using FESEM, XRD, XPS, FTIR, UV/vis., EIS, and CV. The synthesized composite exhibited a low limit of detection (0.03 µM, high sensitivity (0.0014 µA µM-1 cm-2) and wide linear range (0.05-50 µM) for aspartic acid. The substrate, the Co3O4-ZnO nanorod, enhanced the electro-catalytic oxidation of aspartic acid as a result of its catalytic and conductivity properties. The developed sensor based on Co3O4-ZnO has a repeatable, reproducible and stable current response for aspartic acid. Additionally, other electroactive compounds did not interfere with the sensor's current response. The suitability of the developed sensor for real sample analysis was also established. Therefore, this study proposed the potential use of Co3O4-ZnO nanorod material in healthcare management for the maintenance of human well-being.


Assuntos
Nanotubos , Óxido de Zinco , Humanos , Óxido de Zinco/química , Ácido Aspártico , Óxidos/química , Nanotubos/química
6.
Chemosphere ; 315: 137716, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36592839

RESUMO

The unabated usage of priority anthropogenic stressors is a serious concern in the global environmental context. Pharmaceutical drugs such as furazolidone (FL) and nilutamide (NL) have far-reaching repercussions due to the presence of the reactive nitroaromatic moiety. Despite the widespread awareness regarding the dangers posed by nitroaromatic drugs, the promises to alleviate the environmental consequences of drug pollution are often unmet. Accordingly, implementing practices to monitor their presence in various media is a highly desirable, but challenging undertaking. With the advent of deep eutectic solvent-assisted synthesis, it has become possible to fabricate LDH-based sensor materials with minimal energy inputs in a sustainable and scalable manner. In this work, we have framed a series of CoFe-LDH electrocatalysts utilizing deep eutectic solvent-assisted hydrothermal strategies for the simultaneous detection of FL and NL. The CoFe-LDHs intercalated with three distinct anions, namely, (i) Cl-, (ii) SO42-, and (iii) CO32- are compared so as to establish a relationship between anion intercalation and electrochemical activity. Amongst the prepared electrodes, the CF-LDH-ii/SPCE displays highly appreciable selectivity, linear response range (0.09-237.9 µM), low detetion limits (FL = 1.2 nM and NL = 3.8 nM), high sensitivity (FL = 29.71 µA µM⁻1 cm⁻2 and NL = 19.29 µA µM⁻1 cm⁻2), good reproducibility and repeatability towards FL and NL in water and urine samples. Thus, with tailored gallery anions, the proposed electrocatalyst establishes enhanced electrocatalytic performance for the real-time analysis of pharmaceutical contaminants.


Assuntos
Hidróxidos , Nanotubos , Solventes , Reprodutibilidade dos Testes , Solventes Eutéticos Profundos , Carbonatos , Preparações Farmacêuticas
7.
Talanta ; 255: 124245, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-36610258

RESUMO

We introduce here the engineering of nanobiosensors designed from gold nanorods coated with an ultrathin layer of silica (AuNR@SiO2) and biofunctionalized with antibodies for the Localized Surface Plasmon Resonance (LSPR) biosensing of proteins. Despite the outstanding properties of AuNRs, their use for LSPR biosensing is limited due to the presence of the surfactant cetyltrimethylammonium bromide (CTAB) - mandatory for their synthesis - which forms a strongly-bounded and positively-charged bilayer at their surface and significantly complicates their bio-functionalization. When coated with a thin layer of silica, these nanomaterials exhibit an improved sensitivity to refractive index change which augurs for better analytical performances. Here, we undertook an in-depth investigation of the biofunctionalization of AuNR@SiO2via three different routes to design and test a label-free LSPR biosensor operating in solution. In the first route, we took advantage of the negatively charged external silica shell to immobilize anti-rabbit IgG antibody by electrostatic physisorption. In the second and third routes, the silica surface was reacted with thiol or aldehyde terminated silanes, subsequently utilized to covalently attach anti-rabbit IgG antibody to the surface. The resulting nanoprobes were characterized by a wide range of physical methods (TEM, XPS, DLS, ELS and UV-Visible spectroscopy) then tested for the biosensing of rabbit-IgG. The three nanobiosensors maintain an excellent colloidal stability after analyte recognition and exhibit extremely high analytical performances in terms of specificity and dynamic range, with an LoD down to 12 ng/mL.


Assuntos
Técnicas Biossensoriais , Nanotubos , Ressonância de Plasmônio de Superfície/métodos , Ouro/química , Dióxido de Silício/química , Nanotubos/química , Imunoglobulina G
8.
Mikrochim Acta ; 190(2): 54, 2023 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-36642770

RESUMO

An integrated multifunctional light-sheet nanoscopy (iMLSN) combined with differential interference contrast, total internal reflection, epifluorescence, a super-resolution radial fluctuation-stream module, and a wavelength-dependent light sheet was developed to simultaneously realize the six-dimensional (6D) vector-valued (three coordinates + rotational dynamics (azimuth and elevation angles) + transport speed) tracking of anisotropic nanoparticles in single living cells. The wavelength-dependent asymmetric scattering of light by gold nanorods was used to trigger signals depending on the polarizer angle, and real-time photo-switching was achieved by turning the polarizer, obtaining a series of super-resolution images, and tracking using different polarization directions and two channels. This technique was employed to directly observe native gold nanorods (AuNRs; 5 nm diameter × 15 nm length) and surface-functionalized AuNRs during their endocytosis and transport at the upper and attaching side membrane regions of single living cells, revealing that the AuNRs bound to the membrane receptors. The nanorods were subsequently internalized and transported away from the original entry spots. Detailed dynamic information regarding the rotation properties and endocytosis speed during the transmembrane process was also acquired for each region. The developed technique can be considered useful for the real-time monitoring of intracellular transport at various regions in single living cells, as well as for 6D vector-valued non-fluorescence super-resolution imaging and tracking.


Assuntos
Nanopartículas , Nanotubos , Humanos , Células HeLa , Ouro , Transporte Biológico
9.
J Phys Chem Lett ; 14(2): 318-325, 2023 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-36603176

RESUMO

Single-particle spectroelectrochemistry provides optical insight into understanding physical and chemical changes occurring on the nanoscale. While changes in dark-field scattering during electrochemical charging are well understood, changes to the photoluminescence of plasmonic nanoparticles under similar conditions are less studied. Here, we use correlated single-particle photoluminescence and dark-field scattering to compare their plasmon modulation at applied potentials. We find that changes in the emission of a single gold nanorod during charge density tuning of intraband photoluminescence can be attributed to changes in the Purcell factor and absorption cross section. Finally, modulation of interband photoluminescence provides an additional constructive observable, giving promise for establishing dual channel sensing in spectroelectrochemical measurements.


Assuntos
Nanopartículas Metálicas , Nanotubos , Ressonância de Plasmônio de Superfície , Ouro
10.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 58(1): 86-91, 2023 Jan 09.
Artigo em Chinês | MEDLINE | ID: mdl-36642458

RESUMO

Tunneling nanotube (TNT) is a newly discovered communication mode between animal cells in recent years, which have important physiological and pathological significance. However, the role of TNT in bone biology is still unclear. At present, there are many reports about tunneling nanotubes in bone marrow mesenchymal stem cells, osteoclast precursor cells, osteoblasts and immune cells. This review describes the research advances of TNT and its research progress in bone biology. It looks forward to the research direction of TNT in oral and maxillofacial bone development and bone biology, to provide new strategies for the maintenance of bone homeostasis and the treatment of bone diseases.


Assuntos
Osso e Ossos , Nanotubos , Animais , Osteoclastos , Biologia , Comunicação Celular/fisiologia
11.
Chemosphere ; 313: 137591, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36563722

RESUMO

Photoelectrocatalysis (PEC) has long been regarded as an efficient and green method to eliminate various organic pollutants from wastewater. However, the lack of highly photoelectrocatalytic active and stable electrodes limits the development of the PEC technologies. Herein, a novel hierarchical photo-electrode with hollow Cu1.8S/NH2-La MOFs decorated black titanium dioxide nanotubes (Cu1.8S/NH2-La MOFs/Black TNTs) was fabricated by a two-step water-heating method. The prepared photoelectrode was used to degradation of 2, 4-dichlorophenol (2, 4-DCP). Analysis of photoelectrocatalytic degradation process of 2, 4-DCP was evaluated using UV-Vis absorption spectroscopy and the main degradation paths were analyzed by LC-MS. The results showed that 99.3% of the pollutant could be rapidly degraded within 180 min. Furthermore, the Cu1.8S/NH2-La MOFs/Black TNTs photoelectric pole exhibited excellent stability after 15 cycling experiments.


Assuntos
Poluentes Ambientais , Nanotubos , Nanotubos/química , Poluentes Ambientais/química , Fenóis , Eletrodos , Titânio/química , Catálise
12.
Chemosphere ; 313: 137351, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36574576

RESUMO

Photocatalysis has been vastly employed as a feasible and efficient strategy for the removal of environmental pollutants. In this study, a well-designed core-shell heterojunction of WO3 decorated with ZnIn2S4 nanosheets were fabricated under mild in-situ conditions, and fabricated processes were systematically investigated with different fabrication durations. The coupling of WO3 and ZnIn2S4 (ZIS) resulted in a Z-scheme mechanism for charge carrier transfer, holding the respective redox capacity. The as-prepared 1D/2D WO3@ZIS heterostructure displayed the highest removal efficiency within 30 min for 25 mg L-1 Cr(VI), 89.3 and 29.7 times higher than pure WO3 and ZnIn2S4. 1D/2D WO3@ZIS remained excellently stable after 5 cycling experiments. Moreover, 40 mg L-1 RhB could be degraded within 50 min. The broad and short photogenerated electron transportation path is guaranteed by the 1D/2D and Z-scheme charge separation mechanism. It efficiently prevented photo-generated charge carriers from recombination, resulting in a longer carrier lifespan and better photocurrent responses than that of pure ones. This photocatalytic system showed promising results and also provides a framework for an efficient system for photocatalysis with potential for environmental application.


Assuntos
Cromo , Nanotubos , Rodaminas , Excipientes
13.
ACS Biomater Sci Eng ; 9(1): 340-351, 2023 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-36533725

RESUMO

Combinatorial photothermal therapy and chemotherapy is an extremely promising tumor therapeutic modality. However, such systems still remain challenges in stimulus sensitivity, avoiding drug leakage, and therapeutic safety. To solve these problems, we engineered actively loaded doxorubicin (DOX) and gold nanorod (GNR) liposomes through embedding stiff hollow mesoporous silica nanoparticles (HMSNs) in the liposomal water cavity (HMLGDB) to resist the influence of shear force of GNRs to prevent drug leakage. Under 808 nm laser irradiation, the ambient temperature was raised greatly because of the photothermal conversion of GNRs, thereby rupturing the lipid layer and then triggering the DOX release. The results of in vitro experiments showed that the low concentration of HMLGDB (15 µg/mL) could effectively overcome the MCF-7 cells (human breast cancer cell line) by the increase of DOX concentration intracellularly and the good photothermal effect of GNRs. After intravenous injection, HMLGDB exhibited intratumor aggregation and PTT capacity. Furthermore, the combined chemo-photothermal antitumor strategy demonstrated a high inhibition of tumor growth and low damage to normal tissues. The developed hybrids provide a paradigm for efficient combinatorial photothermal therapy (PTT) and chemotherapy (CT).


Assuntos
Hipertermia Induzida , Nanotubos , Neoplasias , Humanos , Lipossomos , Ouro/farmacologia , Doxorrubicina/farmacologia , Neoplasias/tratamento farmacológico
14.
Chemosphere ; 315: 137683, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36586445

RESUMO

Three metal-organic framework (MOF)-based photoanodes were prepared by deposition on TiO2 nanotubes using Ti as substrate (Ti/TiO2NT): i) Ti/TiO2NT-Au@ZIF-8, ii) Ti/TiO2NT-Ru3(BTC)2, iii) Ti/TiO2NT-UiO-66(Zr)NH2. These photoanodes were characterized by FEG-SEM, EDX and DRX. The analyses showed a successful modification and a high homogeneity of the different MOFs on the Ti/TiO2NT surface. The photoanodes were studied in the degradation of Contaminants of Emerging Concern (CECs) in a spiked secondary effluent from a Municipal Wastewater Treatment Plant (MWWTP). Sodium diclofenac (DCF), sulfamethazine (SMT) and carbamazepine (CBZ) were used as CECs at low concentration (200 µg/L each CEC). The samples were preconcentrated using Solid Phase Extraction (SPE) and analyzed by a HPLC-DAD system. The MOF-based photoanodes exhibited a high photoelectrochemical (PEC) activity towards the oxidation of CECs, achieving up to 50%, 70% and 80% of removal using Ti/TiO2NT-Au@ZIF-8, Ti/TiO2NT-UiO-66(Zr)NH2, Ti/TiO2NT-Ru3(BTC), respectively. The influence of the generation of hydroxyl radical was then studied. The results indicate that PEC degradation using Ti/TiO2NT-Ru3(BTC)2 and Ti/TiO2NT-UiO-66(Zr)NH2 is more affected by the concentration of the radical.


Assuntos
Estruturas Metalorgânicas , Nanotubos , Ácidos Ftálicos , Estruturas Metalorgânicas/química , Oxirredução
15.
J Biotechnol ; 362: 36-44, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36563859

RESUMO

Bio-functionalized metal oxide nanoparticles (NPs) have been taken great importance in biomedical fields. The use of nanoparticles as delivery agents of therapeutic molecules led the researchers to emphasize the potential impact of these NPs on bio-macromolecules as protein-nanoparticle complexes, which also extended their importance as vehicles in targeted drug delivery systems due to increased ease of administration, firmness, reduced toxic side effects, and half-life of drugs. Since human serum albumin is the blood protein responsible for transporting materials in the blood system, the interaction of these particles with HSA is essential to be understood before considering the nanoparticles for any individual biomedical application. In the present study, we synthesized zinc-oxide nanorods (ZONRs) using a microwave-assisted synthesis technique, and characterized them by XRD, FTIR, Raman, SEM-EDX, UV-Vis spectroscopy, and photoluminescence (PL) spectroscopy methods. The interaction studies were carried out using fluorescence spectroscopy, and the change in secondary structure was analyzed using CD spectroscopy. The results of MTT cell viability assay demonstrated that the ZONRs has potential cytotoxic properties.


Assuntos
Nanopartículas Metálicas , Nanotubos , Óxido de Zinco , Humanos , Albumina Sérica Humana/metabolismo , Óxido de Zinco/farmacologia , Óxido de Zinco/química , Nanopartículas Metálicas/química , Espectrometria de Fluorescência , Espectroscopia de Infravermelho com Transformada de Fourier
16.
Analyst ; 148(2): 269-277, 2023 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-36510856

RESUMO

Exploring highly active peroxidase mimics at physiological pH is important for the construction of efficient and convenient colorimetric sensing platforms for detecting small biomolecules. In this work, prepared zinc pyrovanadate (Zn3V2O7(OH)2·2H2O) nanorods exhibit excellent peroxidase-like activity, which is verified by the fast oxidation of colorless 3,3',5,5'-tetramethylbenzidine (TMB) into a blue product (oxTMB) by H2O2 at physiological pH (pH = 7) in 2 min. In addition, the catalytic behaviors of Zn3V2O7(OH)2·2H2O as a peroxidase-like nanozyme conform to the Michaelis-Menten equation. Scavenger experiments prove that the catalytic activity of Zn3V2O7(OH)2·2H2O is ascribed to ˙O2- radicals generated in the process of catalysis. Based on the peroxidase-like activity of the Zn3V2O7(OH)2·2H2O nanozyme, a fast and convenient colorimetric sensor has been constructed to detect H2O2 and epinephrine (EP) under physiological pH. The detection limit of EP is as low as 0.26 µM. In addition, the feasibility of the proposed sensor has been validated to detect H2O2 in milk and EP in serum.


Assuntos
Colorimetria , Nanotubos , Peróxido de Hidrogênio/química , Zinco , Peroxidase/química , Peroxidases/química , Corantes/química , Epinefrina , Concentração de Íons de Hidrogênio
17.
Anal Chem ; 95(2): 766-773, 2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36525268

RESUMO

A multiple signal-amplified electrochemiluminescence (ECL) urea sensor was designed based on a self-enhanced probe and SiO2 photonic crystals for dynamic tracking of urea transmembrane transport. The self-enhanced probe (AuNR@Ru-LA) prepared by loading polyethyleneimine (PEI), lactobionic acid (LA), and Ru(dcbpy)32+ on gold nanorods (AuNRs) generated an initial ECL signal, and then the intensity was multiple-amplified by the enhanced light-scattering effect of SiO2 photonic crystals and the co-reaction with urea. The as-prepared sensor exhibited excellent performance for the detection of urea in the range of 1.0 × 10-10 to 1.0 × 10-4 M with a detection limit of 8.8 × 10-11 M at (3σ)/S. The AuNR@Ru-LA probes were labeled on HepG2 cells to construct a cytosensor with a detection range of 1.0 × 103 to 2.0 × 106 cells mL-1. In addition, the dynamic changes of the extracellular urea concentration were tracked by monitoring the ECL signal of the cytosensor to study urea transmembrane transport. The developed strategy realized the amplification of multiple ECL signals and the tracking of urea transmembrane transport, which provided a novel dynamic detection method for small biomolecules.


Assuntos
Técnicas Biossensoriais , Nanotubos , Dióxido de Silício/química , Medições Luminescentes/métodos , Polietilenoimina , Fotometria , Nanotubos/química , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos
18.
J Mater Chem B ; 11(3): 606-617, 2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36533555

RESUMO

Hydrogels are soft materials of great interest in different areas such as chemistry, biology, and therapy. Gels made by the self-assembly of small molecules are known as supramolecular gels. The modulation of their properties by monomer molecular design is still difficult to predict due to the potential impact of subtle structural modifications in the self-assembly process. Herein, we introduce the design principles of a new family of self-assembling cyclic octapeptides of alternating chirality that can be used as scaffolds for the development of self-healing hydrogelator libraries with tunable properties. The strategy was used in the preparation of an amphiphilic cyclic peptide monomer bearing an alkoxyamine connector, which allowed the insertion of different aromatic aldehyde pendants to modulate the hydrophobic/hydrophilic balance and fine-tune the properties of the resulting gel. The resulting amphiphiles were able to form self-healable hydrogels with viscoelastic properties (loss tangent, storage modulus), which were strongly dependent on the nature and number of aromatic moieties anchored to the hydrophilic peptide. Structural studies by SEM, STEM and AFM indicated that the structure of the hydrogels was based on a dense network of peptide nanotubes. Excellent agreement was established between the peptide primary structure, nanotube length distributions and viscoelastic behaviour.


Assuntos
Nanotubos , Peptídeos Cíclicos , Hidrogéis/química , Peptídeos/química , Nanotubos/química
19.
Anal Chem ; 95(2): 1169-1175, 2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36541029

RESUMO

Anisotropic nanomaterials, such as gold nanorods (AuNRs), could be employed as an orientation platform due to their polarization-dependent surface plasmon resonance. However, a variety of factors would affect the dark-field light scattering imaging of anisotropic nanomaterials, resulting in an unstable signal, which is not advantageous to its further application. In this work, the localized surface plasmon resonance properties of a few AuNRs at different angles were excited by polarization with a conventional dark-field microscope, in which it was found that the ratio of AuNRs' light scattering intensity at different polarization angles (I) to that without a polarizer (I0) reflected the orientation information of AuNRs. Furthermore, the light scattering signal ratio between the parallel polarization (Ip) and that without a polarizer (I0) was closely related with the aspect ratio of AuNRs, which could not be affected by external conditions. To verify this concept, a highly sensitive and selective assay of the alkaline phosphatase activity in human serum was successfully developed based on the chemical etching of AuNRs, resulting in a lower aspect ratio and a lesser Ip/I0. This result holds great promise for polarization-dependent colorimetric nanomaterials and single-particle tracers in living cells.


Assuntos
Ouro , Nanotubos , Humanos , Ouro/química , Nanotubos/química , Microscopia , Ressonância de Plasmônio de Superfície , Luz
20.
Anal Chem ; 95(2): 1201-1209, 2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36541430

RESUMO

Accurately obtaining information on the heterogeneity of CTCs at the single-cell level is a very challenging task that may facilitate cancer pathogenesis research and personalized therapy. However, commonly used multicellular population capture and release assays tend to lose effective information on heterogeneity and cannot accurately assess molecular-level studies and drug resistance assessment of CTCs in different stages of tumor metastasis. Herein, we designed a near-infrared (NIR) light-responsive microfluidic chip for biocompatible single-cell manipulation and study the heterogeneity of CTCs by a combination of the lateral flow microarray (LFM) chip and photothermal response system. First, immunomagnetic labeling and a gradient magnetic field were combined to distribute CTCs in different regions of the chip according to the content of surface markers. Subsequently, the LFM chip achieves high single-cell capture efficiency and purity (even as low as 5 CTCs per milliliter of blood) under the influence of lateral fluid and magnetic fields. Due to the rapid dissolution of the gelatin capture structure at 37 °C and the photothermal properties of gold nanorods, the captured single CTC cell can be recovered in large quantities at physiological temperature or released individually at a specific point by NIR. The multifunctional NIR-responsive LFM chip demonstrates excellent performance in capture and site release of CTCs with high viability, which provides a robust and versatile means for CTCs heterogeneity study at the single-cell level.


Assuntos
Nanotubos , Células Neoplásicas Circulantes , Humanos , Células Neoplásicas Circulantes/patologia , Linhagem Celular Tumoral , Microfluídica , Análise de Sequência com Séries de Oligonucleotídeos , Separação Celular
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