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1.
Nano Lett ; 24(22): 6696-6705, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38796774

RESUMO

Ultra-high-field (UHF) magnetic resonance imaging (MRI) stands as a pivotal cornerstone in biomedical imaging, yet the challenge of false imaging persists, constraining its full potential. Despite the development of dual-mode contrast agents improving conventional MRI, their effectiveness in UHF remains suboptimal due to the high magnetic moment, resulting in diminished T1 relaxivity and excessively enhanced T2 relaxivity. Herein, we report a DNA-mediated magnetic-dimer assembly (DMA) of iron oxide nanoparticles that harnesses UHF-tailored nanomagnetism for fault-free UHF-MRI. DMA exhibits a dually enhanced longitudinal relaxivity of 4.42 mM-1·s-1 and transverse relaxivity of 26.23 mM-1·s-1 at 9 T, demonstrating a typical T1-T2 dual-mode UHF-MRI contrast agent. Importantly, DMA leverages T1-T2 dual-modality image fusion to achieve artifact-free breast cancer visualization, effectively filtering interference from hundred-micrometer-level false-positive signals with unprecedented precision. The UHF-tailored T1-T2 dual-mode DMA contrast agents hold promise for elevating the accuracy of MR imaging in disease diagnosis.


Assuntos
Meios de Contraste , DNA , Imageamento por Ressonância Magnética , Imageamento por Ressonância Magnética/métodos , Meios de Contraste/química , Humanos , DNA/química , Camundongos , Nanopartículas Magnéticas de Óxido de Ferro/química , Feminino , Animais , Neoplasias da Mama/diagnóstico por imagem , Nanopartículas de Magnetita/química , Linhagem Celular Tumoral
2.
Small ; 20(16): e2305371, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38018306

RESUMO

Liquid crystalline elastomer (LCE) exhibits muscle-like actuation upon order-disturbed stimulus, offering ample room for designing soft robotic systems. Multimodal LCE is demonstrated to unleash the potential to perform multitasks. However, each actuation mode is typically isolated. In contrast, coordination between different actuation modes based on an MXene-doped LCE is realized, whose actuation can be triggered either by directly heating/cooling or using near-infrared light due to the photo-thermal effect of MXene. As such, the two activation modes (heat and light) not only can work individually to offer stable actuation under different conditions but also can collaborate synergistically to generate more intelligent motions, such as achieving the brake and turn of an autonomous rolling. The principle therefore can diversify the design principles for multifunctional soft actuators and robotics.

3.
Small ; : e2404160, 2024 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-39175379

RESUMO

Dual-mode humidity sensors have received wide attention in recent years due to their great potential in multifunction applications. Herein, following a "two birds with one stone" strategy, a dual-mode and self-powered low humidity sensor based on LiBr-MOF-801 with high response and power generation is proposed. The optimized LiBr-MOF-801-based sensor exhibits impedance-voltage dual-mode sensitivity in the low humidity range of 0-23% relative humidity (RH) with high response (57.1 and 0.61 V), small hysteresis (0.3% RH) and good long-term stability at room temperature (20 °C). Moreover, an integrated humidity power generator is obtained by series connection of the self-powered humidity sensor within 15 cm2, and the output voltage reaches 2.6 V with an output power density of 110 nW cm-2, and can be used as energy, supplying power to commercial electronic equipment even in low humidity. This work provides a new sight for fabricating high-performance, dual-mode, and self-powered low-humidity sensors.

4.
Small ; 20(34): e2401024, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38597755

RESUMO

Exposing different facets on metal-organic frameworks (MOFs) is highly desirable to enhance the performance for various applications, however, exploiting a concise and effective approach to achieve facet-controlled synthesis of MOFs remains challenging. Here, by modulating the ratio of metal precursors to ligands, the facet-engineered iron-based MOFs (Fe-MOFs) exhibits enhanced catalytic activity for Fenton reaction are explored, and the mechanism of facet-dependent performance is revealed in detail. Fully exposed (101) and (100) facets on spindle-shaped Fe-MOFs enable rapid oxidation of colorless o-phenylenediamine (OPD) to colored products, thereby establishing a dual-mode platform for the detection of hydrogen peroxide (H2O2) and triacetone triperoxide (TATP). Thus, a detection limit as low as 2.06 nm is achieved, and robust selectivity against a wide range of common substances (>16 types) is obtained, which is further improved by incorporating a deep learning architecture with an SE-VGG16 network model, enabling precise differentiation of oxidizing agents from captured images. The present strategy is expected will shine light on both the rational synthesis of nanomaterials with modulated morphologies and the exploitation of high-performance trace chemical sensors.

5.
Small ; 20(31): e2400698, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38446055

RESUMO

Triboelectric nanogenerator (TENG) is a promising solution to harvest the low-frequency, low-actuation-force, and high-entropy droplet energy. Conventional attempts mainly focus on maximizing electrostatic energy harvest on the liquid-solid surface, but enormous kinetic energy of droplet hitting the substrate is directly dissipated, limiting the output performance. Here, a dual-mode TENG (DM-TENG) is proposed to efficiently harvest both electrostatic energy at liquid-solid surface from a droplet TENG (D-TENG) and elastic potential energy of the vibrated cantilever from a contact-separation TENG (CS-TENG). Triggered by small droplets, the flexible cantilever beam, rather than conventional stiff ones, can easily vibrate multiple times with large amplitude, enabling frequency multiplication of CS-TENG and producing amplified output charges. Combining with the top electrode design to sufficiently utilize charges at liquid-solid interface, a record-high output charge of 158 nC is realized by single droplet. The energy conversion efficiency of DM-TENG is 2.66-fold of D-TENG. An array system with the specially designed power management circuit is also demonstrated for building self-powered system, offering promising applications for efficiently harvesting raindrop energy.

6.
Small ; 20(33): e2400273, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38552218

RESUMO

Gas bubble formation at electrochemical interfaces can significantly affect the efficiency and durability of electrocatalysts. However, obtaining comprehensive details on bubble evolution dynamics, particularly their dynamic interaction with high-performance structured electrocatalysts, poses a considerable challenge. Herein, dual-mode interference/total internal reflection fluorescence microscopy is introduced, which allows for the simultaneous capture of the evolution pathway of bubbles and the 3D motion of nanoplate electrocatalysts, providing high-resolution and accurate spatiotemporal information. During the hydrogen evolution reaction, the dynamics of hydrogen bubble generation and their interactions with single nanoplate electrocatalysts at the electrochemical interface are observed. The results unveiled that, under constant potential, bubbles initially manifest as fast-moving nanobubbles, transforming into stationary microbubbles subsequently. The morphology of stationary nanoplates regulates the trajectories of these moving nanobubbles while the pinned microbubbles induce the motion of the electrocatalysts. The dual-mode microscopy can be employed to scrutinize numerous multiphase electrochemical interactions with high spatiotemporal resolution, which can facilitate the rational design of high-performance electrocatalysts.

7.
Anal Biochem ; 687: 115433, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38128809

RESUMO

A dual-mode colorimetric and fluorometric sensor based on water soluble silver nanoclusters (AgNCs@PEI) is developed for quantitative and visual detection of ascorbic acid (Asc A). The detection method relies on the Asc A induced aggregation of AgNCs@PEI, which resulted in fluorecsence quenching of the sensor. The clusters exhibited a unique combination of static and collisional quenching with a wide range of dynamic detection (1-105 µM) Linear relationship was observed in the concentration range 102-103 µM using fluorescence and 0.2 × 102-5 × 103 µM using absorbance spectroscopy with respective detection limits of 10.65 µM and 2.49 µM. The corresponding colorimetric and fluorometric changes can be easily monitored by the naked eye with a visual detection limit of 103 µM. AgNCs@PEI were further integrated within a hydrogel for developing a solid-state visual detection platform. Notably, the sensing response of the clusters towards Asc A remained unaltered even after hydrogel integration. Additionally, digital image analysis was adopted, which improved the sensitivity of instrument-free fluorescence detection of Asc A. Analysis by the developed sensor showed excellent recovery percentages of Asc A in spiked urine samples, which further underscores the practical applicability of the sensor.


Assuntos
Colorimetria , Nanopartículas Metálicas , Colorimetria/métodos , Ácido Ascórbico/análise , Hidrogéis , Nanopartículas Metálicas/química , Limite de Detecção
8.
J Fluoresc ; 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38538960

RESUMO

Herein, we developed a sophisticated dual-mode sensor that utilized 3-aminophenylboric acid functionalized carbon dots (APBA-CDs) to accurately detect uric acid (UA). Our innovative process involved synthesizing APBA-CDs that emitted at 369 nm using a one-step hydrothermal method with 3-aminophenylboric acid and L-glutamine as precursors, ethanol and deionized water as solvents. Once UA was introduced to the APBA-CDs, the fluorescence of the system became visibly quenched. The results of Zeta potential, Fourier transformed infrared (FTIR) spectra, fluorescence lifetime, and other characteristics were analyzed to determine that the reaction mechanism was static quenching. This meant that after UA was mixed with APBA-CDs, it combined with the boric acid function on the surface to form complexes, resulting in a decrease in fluorescence intensity and a blue shift in the absorption peak at about 295 nm in the Ultraviolet-visible (UV-vis) absorption spectra. We were pleased to report that we have successfully used the dual-reading platform to accurately detect UA in serum and human urine. It provided a superior quantitative and visual analysis of UA without the involvement of enzymes. We firmly believe that our innovative dual-mode sensor has immense potential in the fields of biosensing and health monitoring.

9.
J Fluoresc ; 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38319519

RESUMO

The oxidized bisindolyl-based amphiphilic, chromogenic probe has been synthesized that can form nanoscopic aggregates in the aqueous medium. Along with solvent polarity and pH of the medium, it was observed that the addition of heavy metal pollutants, like Hg2+ can cause significant alteration in the charge transfer state. This resulted in the immediate change in the solution color from yellow to orange. Additionally, we could excite either the monomer species or the aggregates of the probe by choosing the proper excitation wavelength. Upon exciting at 390 nm, the compound exhibited a broad fluorescence spectrum with maxima at 450 nm, presumably due to twisted state charge transfer. On the contrary, the aggregated species (λex = 465 nm) displayed a comparatively weaker fluorescence band centered at 565 nm. Interestingly, the fluorescence intensity at the 450 nm band experience fluorescence quenching in the presence of Hg2+ ion, while the aggregate emission band remained unaffected. Finally, the present system was utilized for detection of mercury ions in natural water samples.

10.
J Fluoresc ; 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38814526

RESUMO

Recently, dual-mode techniques have garnered considerable attention and have been shown to be effective approaches for biomedical analysis and environmental monitoring. A novel and simple dual-mode spectrophotometric and fluorometric probe based on lignin-derived carbon dots (LCDs) was developed to detect atorvastatin calcium (ATS) in a bulk powder and its commercial product. The synthesized LCDs exhibit exceptional fluorescence characteristics and are highly soluble in water while maintaining reasonable stability. The average particle size of the LCDs was 3.42 ± 1.03 nm. The characterization of the produced LCDs indicated a structure resembling graphene oxide with the presence of several functional groups. The developed LCDs show a good fluorescence quantum yield of 32.2%. The fluorescence of the LCDs is quenched by ATS at an emission wavelength of 315 nm after excitation at 275 nm through dynamic and static quenching mechanisms. The optimal reaction conditions for the dual-mode reaction were a pH of 9 and 0.05 mL of the LCDs, which were measured after 3 min at 30 °C by spectrophotometry, followed by 7 min at 20 °C by fluorometric methods. According to the spectrophotometric results, the response of ATS was linear in the range of 4.0-100.0 µg/mL, while according to the fluorometric results, the dynamic range was 3.0-50.0 µg/mL. The limits of detection (LODs) and the limits of quantification (LOQs) were 0.97 µg/mL and 2.95 µg/mL for the fluorometric method, respectively. The nanoprobe effectively analyzed ATS in medication samples and yielded good results.

11.
Anal Bioanal Chem ; 416(5): 1179-1188, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38148365

RESUMO

A facile and sensitive fluorescent and colorimetric dual-readout assay for detection of acid phosphatase (ACP) was developed via Ce(III) ions-directed aggregation-induced emission (AIE) of glutathione-protected gold nanoclusters (GSH-AuNCs) and oxidase-mimicking activity of Ce(IV) ions. Free Ce(IV) ions exhibited a strong oxidase-mimetic activity, catalytically oxidizing colorless 3,3',5,5'-tetramethylbenzidine (TMB) into its blue product oxTMB in the presence of dissolved O2, thus triggering a remarkable color reaction detected visually. ACP can hydrolyze L-ascorbic acid-2-phosphate (AAP) with the production of ascorbic acid (AA). The AA is able to reduce Ce(IV) ions to Ce(III) ions, thus quenching the oxidase-mimetic activity of Ce(IV) ions. Meanwhile, Ce(III) ions induce AIE of GSH-AuNCs, resulting in the enhancement of the fluorescence signal of GSH-AuNCs. Both the fluorescent and colorimetric dual-mode analysis platforms exhibit a sensitive response to ACP, providing detection limits as low as 0.101 U/L and 0.200 U/L, respectively. Besides, this fabricated dual-mode detection platform holds the potential for analysis of ACP in human serum samples and screening inhibitors for ACP. With good performance and practicability, this study shows promising application in the convenient and reliable determination of ACP activity.


Assuntos
Fosfatase Ácida , Cério , Humanos , Oxirredutases , Colorimetria/métodos , Íons , Limite de Detecção
12.
J Nanobiotechnology ; 22(1): 22, 2024 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-38184620

RESUMO

The accurate preoperative diagnosis and tracking of lung adenocarcinoma is hindered by non-targeting and diffusion of dyes used for marking tumors. Hence, there is an urgent need to develop a practical nanoprobe for tracing lung adenocarcinoma precisely even treating them noninvasively. Herein, Gold nanoclusters (AuNCs) conjugate with thyroid transcription factor-1 (TTF-1) antibody, then multifunctional nanoprobe Au-TTF-1 is designed and synthesized, which underscores the paramount importance of advancing the machine learning diagnosis and bioimaging-guided treatment of lung adenocarcinoma. Bright fluorescence (FL) and strong CT signal of Au-TTF-1 set the stage for tracking. Furthermore, the high specificity of TTF-1 antibody facilitates selective targeting of lung adenocarcinoma cells as compared to common lung epithelial cells, so machine learning software Lung adenocarcinoma auxiliary detection system was designed, which combined with Au-TTF-1 to assist the intelligent recognition of lung adenocarcinoma jointly. Besides, Au-TTF-1 not only contributes to intuitive and targeted visualization, but also guides the following noninvasive photothermal treatment. The boundaries of tumor are light up by Au-TTF-1 for navigation, it penetrates into tumor and implements noninvasive photothermal treatment, resulting in ablating tumors in vivo locally. Above all, Au-TTF-1 serves as a key platform for target bio-imaging navigation, machine learning diagnosis and synergistic PTT as a single nanoprobe, which demonstrates attractive performance on lung adenocarcinoma.


Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Humanos , Fluorescência , Terapia Fototérmica , Adenocarcinoma de Pulmão/diagnóstico por imagem , Adenocarcinoma de Pulmão/tratamento farmacológico , Anticorpos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/tratamento farmacológico , Tomografia Computadorizada por Raios X
13.
Proc Natl Acad Sci U S A ; 118(21)2021 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-34001612

RESUMO

Multimodal imaging-the ability to acquire images of an object through more than one imaging mode simultaneously-has opened additional perspectives in areas ranging from astronomy to medicine. In this paper, we report progress toward combining optical and magnetic resonance (MR) imaging in such a "dual" imaging mode. They are attractive in combination because they offer complementary advantages of resolution and speed, especially in the context of imaging in scattering environments. Our approach relies on a specific material platform, microdiamond particles hosting nitrogen vacancy (NV) defect centers that fluoresce brightly under optical excitation and simultaneously "hyperpolarize" lattice [Formula: see text] nuclei, making them bright under MR imaging. We highlight advantages of dual-mode optical and MR imaging in allowing background-free particle imaging and describe regimes in which either mode can enhance the other. Leveraging the fact that the two imaging modes proceed in Fourier-reciprocal domains (real and k-space), we propose a sampling protocol that accelerates image reconstruction in sparse-imaging scenarios. Our work suggests interesting possibilities for the simultaneous optical and low-field MR imaging of targeted diamond nanoparticles.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Imagem Multimodal/métodos , Imagem Óptica/métodos , Fluorescência , Humanos , Imageamento por Ressonância Magnética/instrumentação , Imagem Multimodal/instrumentação , Nanopartículas/química , Nanopartículas/ultraestrutura , Nitrogênio/química , Imagem Óptica/instrumentação , Imagens de Fantasmas
14.
Foodborne Pathog Dis ; 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38483346

RESUMO

Alpha-hemolysin (Hla) is a major virulence factor secreted by Staphylococcus aureus (S. aureus), which can lyse a variety of mammalian cells and help bacteria evade the host immune system or antibiotics, posing a safety hazard to human health. Therefore, it is critical to establish a quick-responsive and sensitive method for Hla detection to ensure food safety. In this work, a dual-mode immunoassay was developed with both colorimetric and fluorescent readouts for discriminative detection of Hla. The proposed sensing system consists of p-phenylenediamine (PPD) and fluorescein, where fluorescein functions as a fluorescent reporter, and PPD serves a dual function as a colorimetric reporter and fluorescence quencher. Subsequently, the reaction system of this method was optimized, and the detection limit, sensitivity, and specificity were evaluated. Under optimal conditions, the proposed method possesses excellent analytical performance in the range from 0.5 to 500 ng/mL with a limit of detection as low as 0.5 ng/mL. Noteworthy, this method was successfully employed for the detection of Hla in milk with good selectivity and high accuracy. Overall, the dual-mode immunoassay provides a superior platform for the on-site, quantitative, and accurate detection of Hla in food samples.

15.
Mikrochim Acta ; 191(4): 185, 2024 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-38451330

RESUMO

A dual-mode sensor was developed for detecting acetylcholinesterase (AChE) and organophosphorus pesticides (OPs) via bifunctional BSA-CeO2 nanoclusters (NCs) with oxidase-mimetic activity and fluorescence property. The dual-mode sensor has the characteristics of self-calibration and self-verification, meeting the needs of different detection conditions and provide more accurate results. The colorimetric sensor and fluorescence sensor have been successfully used for detecting AChE with limit of detection (LOD) of 0.081 mU/mL and 0.056 mU/mL, respectively, while the LOD for OPs were 0.9 ng/mL and 0.78 ng/mL, respectively. The recovery of AChE was 93.9-107.2% and of OPs was 95.8-105.0% in actual samples. A novel strategy was developed to monitor pesticide residues and detect AChE level, which will motivate future work to explore the potential applications of multifunctional nanozymes.


Assuntos
Acetilcolinesterase , Técnicas de Química Analítica , Praguicidas , Smartphone , Acetilcolinesterase/análise , Hidrogéis , Compostos Organofosforados , Praguicidas/efeitos adversos , Técnicas de Química Analítica/métodos
16.
Mikrochim Acta ; 191(5): 284, 2024 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-38652331

RESUMO

A dual-mode (colorimetric/fluorescence) nanoenzyme-linked immunosorbent assay (NLISA) was developed based on Au-Cu nanocubes generating Prussian blue nanoparticles (PBNPs). It is expected that this method can be used to detect the residues of sulfonamides in the field, and solve the problem of long analysis time and high cost of the traditional method. Sulfadimethoxine (SDM) was selected as the proof-of-concept target analyte. The Au-Cu nanocubes were linked to the aptamer by amide interaction, and the Au-Cu nanocubes, SDM and antibody were immobilized on a 96-well plate using the sandwich method. The assay generates PBNPs by oxidising the Cu shells on the Au-Cu nanocubes in the presence of hydrochloric acid, Fe3+ and K3[Fe (CN)6]. In this process, the copper shell undergoes oxidation to Cu2+ and subsequently Cu2 + further quenches the fluorescence of the carbon point. PBNPs exhibit peroxidase-like activity, oxidising 3,3',5,5'-tetramethylbenzidine (TMB) to OX-TMB in the presence of H2O2, which alters the colorimetric signal. The dual-mode signals are directly proportional to the sulfadimethoxine concentration within the range 10- 3~10- 7 mg/mL. The limit of detection (LOD) of the assay is 0.023 ng/mL and 0.071 ng/mL for the fluorescent signal and the colorimetric signal, respectively. Moreover, the assay was successfully applied to determine sulfadimethoxine in silver carp, shrimp, and lamb samples with satisfactory results.


Assuntos
Carbono , Colorimetria , Cobre , Ferrocianetos , Sulfadimetoxina , Ferrocianetos/química , Sulfadimetoxina/análise , Sulfadimetoxina/química , Cobre/química , Colorimetria/métodos , Carbono/química , Limite de Detecção , Ouro/química , Pontos Quânticos/química , Fluorometria/métodos , Nanopartículas Metálicas/química , Aptâmeros de Nucleotídeos/química , Nanopartículas/química , Animais , Ensaio de Imunoadsorção Enzimática/métodos
17.
Mikrochim Acta ; 191(5): 282, 2024 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-38652326

RESUMO

A novel dual-mode fluorometric and colorimetric sensing platform is reported for determining glutathione S-transferase (GST) by utilizing polyethyleneimine-capped silver nanoclusters (PEI-AgNCs) and cobalt-manganese oxide nanosheets (CoMn-ONSs) with oxidase-like activity. Abundant active oxygen species (O2•-) can be produced through the CoMn-ONSs interacting with dissolved oxygen. Afterward, the pink oxDPD was generated through the oxidation of colorless N,N-diethyl-p-phenylenediamine (DPD) by O2•-, and two absorption peaks at 510 and 551 nm could be observed. Simultaneously, oxDPD could quench the fluorescence of PEI-AgNCs at 504 nm via the inner filter effect (IFE). However, in the presence of glutathione (GSH), GSH prevents the oxidation of DPD due to the reducibility of GSH, leading to the absorbance decrease at 510 and 551 nm. Furthermore, the fluorescence at 504 nm was restored due to the quenching effect of oxDPD on decreased PEI-AgNCs. Under the catalysis of GST, GSH and1-chloro-2,4-dinitrobenzo (CDNB) conjugate to generate an adduct, initiating the occurrence of the oxidation of the chromogenic substrate DPD, thereby inducing a distinct colorimetric response again and the significant quenching of PEI-AgNCs. The detection limits for GST determination were 0.04 and 0.21 U/L for fluorometric and colorimetric modes, respectively. The sensing platform illustrated reliable applicability in detecting GST in real samples.


Assuntos
Cobalto , Colorimetria , Glutationa Transferase , Compostos de Manganês , Nanopartículas Metálicas , Óxidos , Polietilenoimina , Prata , Polietilenoimina/química , Prata/química , Cobalto/química , Óxidos/química , Compostos de Manganês/química , Nanopartículas Metálicas/química , Colorimetria/métodos , Glutationa Transferase/metabolismo , Glutationa Transferase/química , Limite de Detecção , Oxirredutases/química , Oxirredutases/metabolismo , Humanos , Glutationa/química , Oxirredução , Técnicas Biossensoriais/métodos , Fenilenodiaminas/química , Nanoestruturas/química
18.
Mikrochim Acta ; 191(6): 319, 2024 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-38727763

RESUMO

The high-residual and bioaccumulation property of organophosphorus pesticides (OPs) creates enormous risks towards the ecological environment and human health, promoting the research for smart adsorbents and detection methods. Herein, 2D hemin-bridged MOF nanozyme (2D-ZHM) was fabricated and applied to the efficient removal and ultrasensitive dual-mode aptasensing of OPs. On the one hand, the prepared 2D-ZHM contained Zr-OH groups with high affinity for phosphate groups, endowing it with selective recognition and high adsorption capacity for OPs (285.7 mg g-1 for glyphosate). On the other hand, the enhanced peroxidase-mimicking biocatalytic property of 2D-ZHM allowed rapid H2O2-directed transformation of 3,3',5,5'-tetramethylbenzidine to oxidic product, producing detectable colorimetric or photothermal signals. Using aptamers of specific recognition capacity, the rapid quantification of two typical OPs, glyphosate and omethoate, was realized with remarkable sensitivity and selectivity. The limit of detections (LODs) of glyphosate were 0.004 nM and 0.02 nM for colorimetric and photothermal methods, respectively, and the LODs of omethoate were 0.005 nM and 0.04 nM for colorimetric and photothermal methods, respectively. The constructed dual-mode aptasensing platform exhibited outstanding performance for monitoring OPs in water and fruit samples. This work provides a novel pathway to develop MOF-based artificial peroxidase and integrated platform for pollutant removal and multi-mode aptasensing.


Assuntos
Glicina , Glifosato , Hemina , Limite de Detecção , Estruturas Metalorgânicas , Praguicidas , Praguicidas/análise , Praguicidas/química , Estruturas Metalorgânicas/química , Hemina/química , Glicina/análogos & derivados , Glicina/química , Glicina/análise , Colorimetria/métodos , Benzidinas/química , Adsorção , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química , Peróxido de Hidrogênio/química , Dimetoato/análise , Dimetoato/química , Aptâmeros de Nucleotídeos/química , Compostos Organofosforados/análise , Compostos Organofosforados/química
19.
Mikrochim Acta ; 191(6): 352, 2024 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-38806756

RESUMO

Developing convenient and reliable methods for Hg2+ monitoring is highly important. Some precious metal nanomaterials with intriguing peroxidase-like activity have been used for highly sensitive Hg2+ detection. However, H2O2 must be added during these detections, which impedes practical applications of Hg2+ sensors due to its susceptible decomposition by environmental factors. Herein, we discovered that the combination of Hg2+ and palladium metal-organic framework@graphene (Pd-MOF@GNs) exhibits oxidase-like activity (OXD). In the absence of H2O2, this activity not only catalyzes the oxidation of chromogenic substrates such as 3,3',5,5'-tetramethylbenzidine (TMB) or o-phenylenediamine (OPD) to produce a color change but also enhances the electrical signals during OPD oxidation. Based on these properties, an effective and convenient dual-mode colorimetric and electrochemical sensor for Hg2+ has been developed. The colorimetric and amperometric linear relationships for Hg2+ were 0.045 µM-0.25 mM and 0.020 µM-2.0 mM, respectively. The proposed strategy shows good recovery in real sample tests, indicating promising prospects for multiple environmental sample detection of Hg2+ without relying on H2O2. The colorimetric and electrochemical dual-mode Hg2+ sensor is expected to hold great potentials in applications such as environmental monitoring, rapid field detection, and integration into smartphone detection of Hg2+.


Assuntos
Colorimetria , Técnicas Eletroquímicas , Grafite , Limite de Detecção , Mercúrio , Estruturas Metalorgânicas , Paládio , Grafite/química , Colorimetria/métodos , Mercúrio/análise , Mercúrio/química , Estruturas Metalorgânicas/química , Paládio/química , Técnicas Eletroquímicas/métodos , Benzidinas/química , Oxirredução , Poluentes Químicos da Água/análise , Peróxido de Hidrogênio/química , Peróxido de Hidrogênio/análise , Oxirredutases/química , Oxirredutases/metabolismo , Fenilenodiaminas/química
20.
Mikrochim Acta ; 191(9): 515, 2024 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-39105818

RESUMO

A smartphone-assisted portable dual-mode immunoassay was constructed based on curcumin nanoparticles (CNPs) and carbon dots (CDs) for gentamicin (GEN) detection. CNPs were labeled with goat anti-mouse IgG (Ab2) to create a conjugation that coupled dual signals to concentrations of GEN antigens. CNPs were introduced to pH 7.4 water and showed insignificant color and optical responses. When exposed to the high pH environment, the structure of CNPs changed and color and optical properties were restored. Because of the inner filter effect (IFE) between CNPs and CDs, the fluorescence of CNPs at 550 nm quenched the fluorescence of CDs at 450 nm. Colorimetry and ratiometric fluorescence (F550 nm/F450 nm) dual-mode immunoassay linearly correlated with GEN ranged from 10-4 to 100 µg/mL with a detection limit (LOD) of 8.98 × 10-5 µg/mL and 4.66 × 10-5 µg/mL, respectively. This work supplied a portable, sensitive, and specific platform to detect GEN.


Assuntos
Carbono , Curcumina , Gentamicinas , Limite de Detecção , Nanopartículas , Pontos Quânticos , Smartphone , Curcumina/química , Imunoensaio/métodos , Carbono/química , Gentamicinas/análise , Gentamicinas/imunologia , Gentamicinas/química , Pontos Quânticos/química , Nanopartículas/química , Animais , Camundongos
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