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1.
Ecotoxicol Environ Saf ; 284: 116986, 2024 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-39241609

RESUMEN

A new and highly sensitive voltammetric technique was described in this study for the concurrent detection of endocrine disruptors bisphenol A (BPA) and bisphenol AF (BPAF) based on carbon nanocages (CNCs) and copper oxide nanochains (CuONCs). The CNCs was prepared by the solvothermal method and characterized using various techniques. Utilizing the nanocomposite of CNCs and CuONCs, the voltammetric sensor demonstrated outstanding performance in detecting BPA and BPAF simultaneously with distinct oxidation peaks and increased current peaks. The voltammetric signals have linear relationships with the two bisphenols ranging from 0.500 µM to 100 µM with a detection limit of 0.16 µM for BPA and 0.14 µM for BPAF. The newly designed sensor showed reliable consistency, long-term durability and anti-interference ability, and performed well in analyzing real water samples, indicating great potential for environmental monitoring.


Asunto(s)
Compuestos de Bencidrilo , Carbono , Cobre , Técnicas Electroquímicas , Disruptores Endocrinos , Fenoles , Contaminantes Químicos del Agua , Fenoles/análisis , Fenoles/química , Compuestos de Bencidrilo/análisis , Compuestos de Bencidrilo/química , Cobre/análisis , Cobre/química , Disruptores Endocrinos/análisis , Disruptores Endocrinos/química , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/química , Carbono/química , Técnicas Electroquímicas/métodos , Monitoreo del Ambiente/métodos , Límite de Detección , Nanocompuestos/química , Fluorocarburos
2.
Small ; 19(7): e2205079, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36504439

RESUMEN

Magnetic nanoparticle chains offer the anisotropic magnetic properties that are often desirable for micro- and nanoscale systems; however, to date, large-scale fabrication of these nanochains is limited by the need for an external magnetic field during the synthesis. In this work, the unique self-assembly of nanoparticles into chains as a result of their intrinsic dipolar interactions only is examined. In particular, it is shown that in a high concentration reaction regime, the dipole-dipole coupling between two neighboring magnetic iron cobalt (FeCo) nanocubes, was significantly strengthened due to small separation between particles and their high magnetic moments. This dipole-dipole interaction enables the independent alignment and synthesis of magnetic FeCo nanochains without the assistance of any templates, surfactants, or even external magnetic field. Furthermore, the precursor concentration ([M] = 0.016, 0.021, 0.032, 0.048, 0.064, and 0.096 m) that dictates the degree of dipole interaction is examined-a property dependent on particle size and inter-particle distance. By varying the spinner speed, it is demonstrated that the balance between magnetic dipole coupling and fluid dynamics can be used to understand the self-assembly process and control the final structural topology from that of dimers to linear chains (with aspect ratio >10:1) and even to branched networks. Simulations unveil the magnetic and fluid force landscapes that determine the individual nanoparticle interactions and provide a general insight into predicting the resulting nanochain morphology. This work uncovers the enormous potential of an intrinsic magnetic dipole-induced assembly, which is expected to open new doors for efficient fabrication of 1D magnetic materials, and the potential for more complex assemblies with further studies.

3.
Small ; 19(16): e2206105, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36683240

RESUMEN

Herein, for the first time, the CRISPR-Cas12a system is combined with aptamer, cascaded dynamic DNA network circuits, and Fe3 O4 @hollow-TiO2 @MoS2 nanochains (Fe3 O4 @h-TiO2 @MoS2 NCs) to construct an efficient sensing platform for tetracycline (TC) analysis. In this strategy, specific recognition of the target is transduced and amplified into H1-H2 duplexes containing the specific sequence of Cas12a-crRNA through an aptamer recognition module and the dual amplification dynamic DNA network. Subsequently, the obtained activated Cas12a protein non-specifically cleaves the adjacent reporter gene ssDNA-FAM to dissociate the FAM molecule from the quencher Fe3 O4 @h-TiO2 @MoS2 NCs, resulting in the recovery of the fluorescence signal and further signal amplification. Particularly, the synthesized multifunctional Fe3 O4 @h-TiO2 @MoS2 NCs composites also exhibit superb magnetic separability and photocatalytic degradation ability. Under optimal conditions, the aptasensor displays a distinct linear relationship with the logarithm of TC concentration, and the limit of detection is as low as 0.384 pg mL-1 . Furthermore, the results of spiked recovery confirm the viability of the proposed aptasensor for TC quantification in real samples. This study extends the application of the CRISPR-Cas12a system in the field of analytical sensing and contributes new insights into the exploration of reliable tools for monitoring and treating hazards in food and environment.


Asunto(s)
Técnicas Biosensibles , Sistemas CRISPR-Cas , Antibacterianos , Colorantes , Sistemas CRISPR-Cas/genética , ADN , Molibdeno , Oligonucleótidos , Tetraciclina , Colorantes Fluorescentes
4.
Chemistry ; 29(32): e202300522, 2023 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-36912574

RESUMEN

The electroreduction of carbon dioxide (CO2 ) is a sustainable method for generating valuable chemicals; however, avoiding unwanted hydrogen (H2 ) production during the electrolysis is a major challenge. Coproduction of carbon monoxide (CO) and H2 to produce syngas is an effective strategy for solving this problem, and syngas with a desired CO/H2 ratio can be employed to produce methanol or other valuable chemicals. Herein, a series of palladium-bismuth (Pd-Bi) bimetallic nanochains with different Pd/Bi atomic ratios were prepared and used in the electroreduction of CO2 to syngas in ionic liquid-based electrolytes. The ratio of CO/H2 in syngas was regulated in a wide range from 1 : 7 to 9 : 1 by controlling the applied potentials, Pd/Bi atomic ratios and composition of the electrolytes. In particular, the current density reached 19.3 mA cm-2 on Pd3 Bi bimetallic nanochains at an applied potential of -2.3 V versus Ag/Ag+ when the CO/H2 ratio was approximately 1 : 1. Moreover, the maximum CO Faradaic efficiency was 87.7 % for these electrocatalysts at an applied potential of -2.0 V versus Ag/Ag+ . The synergistic effect of Pd and Bi in the ionic liquid-based electrolyte was the primary reason for the distinct electrocatalytic efficiency of the Pd3 Bi bimetallic nanochains. The incorporation of moderate amounts of Bi into the Pd lattice resulted in a stronger CO2 adsorption capacity, more active sites and faster electron transfer rate, which are conducive to improving the electrocatalytic activity.


Asunto(s)
Bismuto , Líquidos Iónicos , Dióxido de Carbono , Paladio , Electrólitos
5.
Nanotechnology ; 34(32)2023 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-37160113

RESUMEN

The zerovalent iron (Fe0) nanomaterials tend to be spontaneously oxidized in the presence of oxygen. This leads to the formation of interface composed of iron core and thin iron oxide shell. These structures are frequently observed with transmission electron microscope but, at the same time, it is hard to determine the precise structural and chemical composition of oxide shell. This feature is very important for possible applications of Fe0nanostructures. Hence, the present work aims to deliver more detailed insights in this topic. The investigations are performed for the iron nanochains prepared in the magnetic-field-induce reduction of FeCl3by NaBH4. The high-resolution transmission electron microscopy, electron energy loss spectroscopy, and x-ray photoemission spectroscopy confirm that the iron nanochains are covered by very thin oxide layer not exceeding over 3 nm. Moreover, the detailed XPS analyses of O 1s and Fe 2p lines indicate that the iron oxide shell reveals Fe3O4nature. Moreover, this work demonstrated that some by-products of the reaction containing boron are presented in the sample even after a removal of the thin iron oxide shell by Ar+treatment.

6.
Ecotoxicol Environ Saf ; 252: 114588, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36724711

RESUMEN

Gold nanochains (AuNCs) were prepared, and this novel material was combined with carboxylated multi-walled carbon nanotubes (cMWCNTs) to be a nanocomposite for the first time. The transmission electron microscopy (TEM), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and UV-Vis spectra were used to characterize the successful preparation of AuNCs and AuNC-cMWCNT composite. Based on this hybrid material, a voltammetric sensor of bisphenol A (BPA) was established. The proposed sensor displayed excellent performance for the measurement of BPA by obvious decreased anodic peak potential and enlarged peak current. Using the optimized conditions, BPA was detected using linear sweep voltammetry, and the linear range showed as wide as 0.5 µM to 2000 µM with the detection limit estimated to be 12 nM (S/N = 3). The as-proposed sensor also exhibited satisfactory performance in determining BPA of actual plastic samples.


Asunto(s)
Nanotubos de Carbono , Nanotubos de Carbono/química , Oro/química , Técnicas Electroquímicas/métodos , Fenoles/química , Electrodos
7.
Small ; 18(21): e2200662, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35460197

RESUMEN

Magnetic photonic crystals (PCs) possess attractive magnetic orientation, flexible pattern designability, and abundant angle-dependent colors, providing immense potential in anticounterfeiting field. However, all-solid magnetic PCs-based labels generally suffer from incompatibility with screen printing techniques, and inferior environmental endurance and mechanical properties. Herein, by developing a selective concentration polymerization method under magnetic field (H) in microheterogenous dimethyl sulfoxide-water binary solvents, individual tens-of-micrometer-length lipophilic magnetic photonic nanochains (PNCs) of full-width at half-maxima below 30 nm are fabricated, which, after simply dispersed in solvent-free cycloaliphatic epoxy resin, can be formulated as photonic inks to print robust anticounterfeiting labels through an H-assisted screen-printing technology. The as-printed labels possess vivid optically variable effects (OVEs) associated with the spatial distribution of H directionality, which are easy to identify by the naked eye but difficult to imitate and duplicate, while they show excellent environmental resistance and mechanical properties, promising practical applications in banknotes and high-grade commodities. The polymerization mechanism of the lipophilic PNCs is elucidated, and the OVEs are deciphered in numerical simulation. Besides an efficient way to build organic-inorganic hybrid nanostructures, the work provides advanced structural color pigments to achieve the practical application of magnetic PCs in such an anticounterfeiting field.

8.
Nano Lett ; 20(2): 803-811, 2020 02 12.
Artículo en Inglés | MEDLINE | ID: mdl-29323918

RESUMEN

Microenvironment sensing and imaging are of importance in microscale zones like microreactors, microfluidic systems, and biological cells. But they are so far implemented only based on chemical colors from dyes or quantum dots, which suffered either from photobleaching, quenching, or photoblinking behaviors, or from limited color gamut. In contrast, structural colors from hydrogel-based photonic crystals (PCs) may be stable and tunable in the whole visible spectrum by diffraction peak shift, facilitating the visual detection with high accuracy. However, the current hydrogel-based PCs are all inappropriate for microscale detection due to the bulk size. Here we demonstrate the smallest hydrogel-based PCs, responsive hydrogel-based photonic nanochains with high-resolution and real-time response, by developing a general hydrogen bond-guided template polymerization method. A variety of mechanically separated stimuli-responsive hydrogel-based photonic nanochains have been obtained in a large scale including those responding to pH, solvent, and temperature. Each of them has a submicrometer diameter and is composed of individual one-dimensional periodic structure of magnetic particles locked by a tens-of-nanometer-thick peapod-like responsive hydrogel shell. Taking the pH-responsive hydrogel-based photonic nanochains, for example, pH-induced hydrogel volume change notably alters the nanochain length, resulting in a significant variation of the structural color. The submicrometer size endows the nanochains with improved resolution and response time by 2-3 orders of magnitude than the previous counterparts. Our results for the first time validate the feasibility of using structural colors for microenvironment sensing and imaging and may further promote the applications of responsive PCs, such as in displays and printing.

9.
Angew Chem Int Ed Engl ; 60(45): 24234-24240, 2021 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-34494351

RESUMEN

Fast and ultrasensitive detection of pathogens is very important for efficient monitoring and prevention of viral infections. Here, we demonstrate a label-free optical detection approach that uses a printed nanochain assay for colorimetric quantitative testing of viruses. The antibody-modified nanochains have high activity and specificity which can rapidly identify target viruses directly from biofluids in 15 min, as well as differentiate their subtypes. Arising from the resonance induced near-field enhancement, the color of nanochains changes with the binding of viruses that are easily observed by a smartphone. We achieve the detection limit of 1 PFU µL-1 through optimizing the optical response of nanochains in visible region. Besides, it allows for real-time response to virus concentrations ranging from 0 to 1.0×105  PFU mL-1 . This low-cost and portable platform is also applicable to rapid detection of other biomarkers, making it attractive for many clinical applications.


Asunto(s)
Colorimetría , Virus/aislamiento & purificación , Biomarcadores/análisis
10.
Nano Lett ; 19(7): 4752-4759, 2019 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-31189063

RESUMEN

Developing high-performance electrocatalysts for the ethanol oxidation reaction (EOR) is critical to the commercialization of direct ethanol fuel cells. However, current EOR catalysts suffer from high cost, low activity, and poor durability. Here we report the preparation of PdBi-Bi(OH)3 composite nanochains with outstanding EOR activity and durability. The incorporation of Bi can tune the electronic structure and downshift the d-band center of Pd while the surface decoration of Bi(OH)3 can facilitate the oxidative removal of CO and other carbonaceous intermediates. As a result, the nanochains manifest an exceptional mass activity (5.30 A mgPd-1, 4.6-fold higher than that of commercial Pd/C) and outstanding durability (with a retained current density of ∼1.00 A mgPd-1 after operating for 20 000 s). More importantly, the nanochain catalyst can be reactivated, and negligible activity loss has been observed after operating for 200 000 s with periodic reactivation, making it one of the best EOR catalysts.

11.
Small ; 15(1): e1804212, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30515971

RESUMEN

The development of cost-efficient, active, and stable electrode materials as bifunctional catalysts for electrochemical water splitting is crucial to high-performance renewable energy storage and conversion devices. In this work, the synthesis of Co-based multi-metal borides nanochains with amorphous structure is reported for boosting the oxygen evolution (OER) and hydrogen evolution reactions (HER) by one-pot NaBH4 reduction of Co2+ , Ni2+ , and Fe2+ under ambient temperature. In all the investigated Co-based metal borides, NiCoFeB nanochains show the excellent OER performance with a low overpotential of 284 mV at 10 mA cm-2 and Tafel slope of 46 mV dec-1 , respectively, together with excellent catalytic stability, and robust HER performance with an overpotential of 345 mV at 10 mA cm-2 . The density functional theory (DFT) calculations reveal that the excellent electrocatalytic performance is mainly attributed to optimal electronic structure by tuning the Co-3d band activities by the incorporation of Ni and Fe for enhanced water splitting via the potentially existed Co0 state. Moreover, the electrolyzer using NiCoFeB nanochains as anode and cathode offers 10 mA cm-2 at a cell voltage of 1.81 V, comparable to commercial Pt/C // Ir/C, providing a simple method to design and explore highly efficient and cheap bifunctional electrocatalysts for overall water splitting.

12.
Ecotoxicol Environ Saf ; 172: 167-175, 2019 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-30708228

RESUMEN

In this study, platinum nanochains (PtNCs), multi-walled carbon nanotubes (MWCNTs) and graphene nanoparticles (GNPs) were assembled together to form a novel nanocomposite by a facile ultrasonic-assisted blending process. The PtNCs-MWCNTs-GNPs nanocomposite was characterized by high resolution transmission electron microscopy (HR-TEM), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The nanocomposite was used for the modification of glass carbon electrode (GCE) and simultaneous determination of dopamine (DA) and ascorbic acid (AA) by differential pulse voltammetry (DPV) and cycle voltammetry (CV). Under the optimum conditions, the calibration curves obtained are linear for the currents versus DA and AA concentrations over the range 2.00-50.0 µM and 100-1200 µM, respectively. And the detection limits for DA and AA are 0.500 µM and 10.0 µM, respectively. The detection and quantitative analysis of DA and AA in human serum and vitamin C tablets on PtNCs-MWCNTs-GNPs/GCE gave the recoveries of 104-110% and 101-108% with relative standard deviations (RSD) of 4.36-7.48% and 0.620-2.90%, respectively. The proposed PtNCs-MWCNTs-GNPs composite could provide a new platform for the routine analysis of DA and AA in terms of its good anti-interference ability, excellent reproducibility and repeatability, and feasibility of use.


Asunto(s)
Ácido Ascórbico/análisis , Dopamina/análisis , Platino (Metal)/química , Ácido Ascórbico/sangre , Técnicas Biosensibles , Dopamina/sangre , Técnicas Electroquímicas , Electrodos , Grafito/química , Humanos , Límite de Detección , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Nanocompuestos/química , Nanopartículas/química , Nanotubos de Carbono/química , Reproducibilidad de los Resultados
13.
Chemistry ; 24(9): 2157-2163, 2018 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-29205557

RESUMEN

The route of converting CO2 to CO by reverse water-gas shift (RWGS) reaction is of particular interest due to the direct use of CO as feedstock in many significant industrial processes. Here, an engineered cobalt-cobalt oxide core-shell catalyst (Co@CoO) with nanochains structure has been made for the efficient reduction of CO2 to useful CO. Owing to the excellent performance for H2 activation of metal nanoparticles and the enhanced absorption and activation for CO2 molecule of defective metal oxides, the unique synergistic effect of metallic Co and encapsulating coordinatively unsaturated CoO species shows high performance for clean generation of CO under moderate and practical conditions. Furthermore, with N-dopant into the defective CoO shell, the Co@CoO-N achieves the highest conversion of 19.2 % and an exceptional CO evolution rate of 96 mL min-1 gcat-1 at 523 K with a gas hourly space velocity (GHSV) of 42,000 mL gcat-1 h-1 , which is comparable with the previously reported materials under identical conditions.

14.
Chemistry ; 24(15): 3707-3711, 2018 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-29356148

RESUMEN

Metal alloy nanoparticles have shown promising applications in electrocatalysis. However, the nanoparticles usually suffer from limited charge-transfer efficiency, which can be solved by preparing one-dimensional materials. Herein, Co-Ni alloy nanochains are prepared by a direct-current arc-discharge method. The nanochains, comprised of mutually coupled uniform nanospheres, can range up to several micrometers in size. When the alloy is exposed to air or under the electro-oxidation process, a metal-metal-oxide heterostructure is obtained. The alloy can inject electrons into the oxide, which makes it more suitable for electrocatalysis. The composition of the samples can be changed by varying the ratio of Ni/Co (i.e., Co, Co7 Ni3 , Co5 Ni5 , Co3 Ni7 , Ni) in the synthesis process. The nanochains show good oxygen evolution performance that correlates with the Ni/Co ratio. Co7 Ni3 demonstrates optimal activity with an onset point of 1.50 V vs. reversible hydrogen electrode (RHE) and overpotential of 350 mV at 10 mA cm-2 . The alloy nanochains also show excellent durability with 95.0 % current retention after a long-term test for 12 h.

15.
Angew Chem Int Ed Engl ; 53(18): 4614-7, 2014 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-24623368

RESUMEN

A facile in situ method to grow Au nanoparticles (NPs) in hexaniobate nanoscrolls is applied to the formation of plasmonic Au@hexaniobate and bifunctional plasmonic-magnetic Au-Fe3 O4 @hexaniobate nanopeapods (NPPs). Utilizing a solvothermal treatment, rigid multiwalled hexaniobate nanoscrolls and partially filled Fe3 O4 @hexaniobate NPPs were first fabricated. These nanostructures were then used as templates for the controlled in situ growth of Au NPs. The resulting peapod structures exhibited high filling fractions and long-range uniformity. Optical measurements showed a progressive red shift in plasmonic behavior between Au NPs, Au NPPs, and Au-Fe3 O4 NPPs; magnetic studies found that the addition of gold in the Fe3 O4 @hexaniobate NPPs reduced interparticle coupling effects. The development of this approach allows for the routine bulk preparation of noble-metal-containing bifunctional nanopeapod materials.

16.
Nanomaterials (Basel) ; 14(11)2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38869588

RESUMEN

Diabetes is a common disease that seriously endangers human health. Continuous glucose monitoring (CGM) is important for the prevention and treatment of diabetes. Glucose-sensing photonic nanochains (PNCs) have the advantages of naked-eye colorimetric readouts, short response time and noninvasive detection of diabetes, showing immense potential in CGM systems. However, the developed PNCs cannot disperse in physiological environment at the pH of 7.4 because of their poor hydrophilicity. In this study, we report a new kind of PNCs that can continuously and reversibly detect the concentration of glucose (Cg) in physiological environment at the pH of 7.4. Polyacrylic acid (PAA) added to the preparation of PNCs forms hydrogen bonds with polyvinylpyrrolidone (PVP) in Fe3O4@PVP colloidal nanoparticles and the hydrophilic monomer N-2-hydroxyethyl acrylamide (HEAAm), which increases the content of PHEAAm in the polymer shell of prepared PNCs. Moreover, 4-(2-acrylamidoethylcarbamoyl)-3-fluorophenylboronic acid (AFPBA), with a relatively low pKa value, is used as the glucose-sensing monomer to further improve the hydrophilicity and glucose-sensing performances of PNCs. The obtained Fe3O4@(PVP-PAA)@poly(AFPBA-co-HEAAm) PNCs disperse in artificial serum and change color from yellow-green to red when Cg increases from 3.9 mM to 11.4 mM, showing application potential for straightforward CGM.

17.
ACS Nano ; 18(22): 14595-14604, 2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38758185

RESUMEN

Defect engineering and nitrogen doping being effective strategies for modulating the surface chemical state of the carbon matrix have been widely explored to promote the catalytic activity in the territory of electrochemical energy storage and conversion devices. However, the controllable synthesis of carbon material with high-density specific defects and high nitrogen doping is still full of challenges. Here, we first synthesize one-dimensional necklace-like nitrogen-doped carbon nanochains (N-CNCs) with abundant defects on carbon fiber paper (CFP) by chemical vapor deposition (CVD) method. The resultant nanostructures are a bunch of interconnected carbon spheres with a hollow structure at the internode and present the complete one-dimensional nanochain configuration. Specifically, the N-CNCs with a corrugated surface possesses high content of sp3 defects (31.2%) and nitrogen (23.6 at %). Combining finite element analysis and experimental results, it reveals that the robust shear field generated by etching gas releasing from thermal decomposition of melamine in situ modulates the CVD process via changing the size and force environment of the metal catalyst droplets for formation of N-CNCs. Benefiting from the high ratio of sp3/sp2 and nitrogen doped on the surface, the N-CNCs@CFP displays a superior electrocatalytic performance for CO2RR, delivering CO Faradaic efficiency of 95.9% and a current density of 23.2 mA cm-2 at -0.86 V vs RHE. This work provides promising synthesis strategy and some inspirations for construction of ultradense and specific defects coupling with nitrogen doping sites into carbon materials to achieve high-efficiency electrocatalysis applications.

18.
Polymers (Basel) ; 16(11)2024 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-38891476

RESUMEN

Responsive photonic crystal hydrogel sensors are renowned for their colorimetric sensing ability and can be utilized in many fields such as medical diagnosis, environmental detection, food safety, and industrial production. Previously, our group invented responsive photonic nanochains (RPNCs), which improve the response speed of photonic crystal hydrogel sensors by at least 2 to 3 orders of magnitude. However, RPNCs are dispersed in a liquid medium, which needs a magnetic field to orient them for the generation of structural colors. In addition, during repeated use, the process of cleaning and redispersing can cause entanglement, breakage, and a loss of RPNCs, resulting in poor stability. Moreover, when mixing with the samples in liquid, the RPNCs may lead to the contamination of the samples being tested. In this paper, we incorporate one-dimensional oriented RPNCs with agarose gel film to prepare heterogeneous hydrogel films. Thanks to the non-responsive and porous nature of the agarose gel, the protons diffuse freely in the gel, which facilitates the fast response of the RPNCs. Furthermore, the "frozen" RPNCs in agarose gel not only enable the display of structural colors without the need for a magnet but also improve the cycling stability and long-term durability of the sensor, and will not contaminate the samples. This work paves the way for the application of photonic crystal sensors.

19.
ACS Nano ; 18(23): 14893-14906, 2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38801653

RESUMEN

Stem cell therapies are gaining traction as promising treatments for a variety of degenerative conditions. Both clinical and preclinical studies of regenerative medicine are hampered by the lack of technologies that can evaluate the migration and behavior of stem cells post-transplantation. This study proposes an innovative method to longitudinally image in vivo human-induced pluripotent stem cells differentiated to retinal pigment epithelium (hiPSC-RPE) cells by multimodal photoacoustic microscopy, optical coherence tomography, and fluorescence imaging powered by ultraminiature chain-like gold nanoparticle cluster (GNC) nanosensors. The GNC exhibits an optical absorption peak in the near-infrared regime, and the 7-8 nm size in diameter after disassembly enables renal excretion and improved safety as well as biocompatibility. In a clinically relevant rabbit model, GNC-labeled hiPSC-RPE cells migrated to RPE degeneration areas and regenerated damaged tissues. The hiPSC-RPE cells' distribution and migration were noninvasively, longitudinally monitored for 6 months with exceptional sensitivity and spatial resolution. This advanced platform for cellular imaging has the potential to enhance regenerative cell-based therapies.


Asunto(s)
Oro , Imagen Multimodal , Epitelio Pigmentado de la Retina , Conejos , Animales , Humanos , Oro/química , Epitelio Pigmentado de la Retina/citología , Trasplante de Células Madre , Tomografía de Coherencia Óptica , Nanopartículas del Metal/química , Células Madre Pluripotentes Inducidas/citología , Movimiento Celular , Diferenciación Celular , Imagen Óptica , Técnicas Fotoacústicas
20.
Nanomaterials (Basel) ; 13(19)2023 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-37836273

RESUMEN

Double bandgap photonic crystals (PCs) exhibit significant potential for applications in various color display-related fields. However, they show low color saturation and inadequate color modulation capabilities. This study presents a viable approach to the fabrication of double bandgap photonic inks diffracting typical secondary colors and other composite colors by simply mixing two photonic nanochains (PNCs) of different primary colors as pigments in an appropriate percentage following the conventional RGB color matching method. In this approach, the PNCs are magnetically responsive and display three primary colors that can be synthesized by combining hydrogen bond-guided and magnetic field (H)-assisted template polymerization. The as-prepared double bandgap photonic inks present high color saturation due to the fixed and narrow full-width at half-maxima of the parent PNCs with a suitable chain length. Furthermore, they can be used to easily produce a flexible double bandgap PC film by embedding the PNCs into a gel, such as polyacrylamide, facilitating fast steady display performance without the requirement of an external magnetic field. This research not only presents the unique advantages of PNCs in constructing multi-bandgap PCs but also establishes the feasibility of utilizing PNCs in practical applications within the fields of anti-counterfeiting and flexible wearable devices.

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