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1.
Anal Chem ; 94(4): 2263-2270, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-35050594

RESUMO

Here, we present a wearable potentiometric ion sensor for real-time monitoring of sodium ions (Na+) in human sweat samples using Na0.44MnO2 as the sensing material. Na0.44MnO2 is an attractive material for developing wearable electrochemical sensors due to its good Na+ incorporation ability, electrical conductivity, stability, and low fabrication cost. In the first step, the analytical performance of the electrode prepared using Na0.44MnO2 is presented. Then, a miniaturized potentiometric cell integrated into a wearable substrate is developed, which reveals a Nernstian response (58 mV dec-1). We achieved the detection of Na+ in the linear ranges of 0.21-24.54 mmol L-1, which is well within the physiological range of Na+. Finally, for on-body sweat analysis, the potentiometric sensor is fully integrated into a headband textile. This platform can be employed for non-invasive analysis of Na+ in human sweat for healthcare and disease diagnosis.


Assuntos
Técnicas Biossensoriais , Dispositivos Eletrônicos Vestíveis , Humanos , Íons , Compostos de Manganês , Óxidos , Sódio , Suor
2.
Mikrochim Acta ; 190(1): 37, 2022 12 26.
Artigo em Inglês | MEDLINE | ID: mdl-36571644

RESUMO

It was demonstrated that the mechanism of the inner filter effect (IFE) can emerge well in the resonance Rayleigh scattering (RRS) technique and be utilized as a new analytical method in the design of innovative IFE-based sensors. To prove this process, silver nanocubes (Ag NCs) with tunable extinction spectra were selected as RRS probes, and three analytes, doxorubicin (DOX), sunitinib (SUN), and Alizarin Red S (ARS), were considered as the typical absorbers. In addition, in the presence of SUN as a typical analyte, the quenching of the RRS signal of Ag NCs, with λmax of 419 nm, was linear in the range 0.01 to 2.5 µM of SUN. The limit of detection (LOD) was 0.0025 µM. The introduced method was then used to develop a dual-signal assay for the ratiometric determination of Al3+ ions. The suggested dual-signal assay was based on the color changes of ARS caused by Al3+ and the IFE between ARS and Ag NCs. The obtained results showed that the two characteristics of response sensitivity and linear dynamic range are very satisfactory for sensing Al3+ ions. The findings of this study demonstrate that the newly developed IFE mechanism can be employed as an attractive and highly efficient analytical technique for measuring different analytes.


Assuntos
Prata , Espalhamento de Radiação , Limite de Detecção , Íons
3.
Int J Mol Sci ; 23(24)2022 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-36555829

RESUMO

Biomaterials for tissue scaffolds are key components in modern tissue engineering and regenerative medicine. Targeted reconstructive therapies require a proper choice of biomaterial and an adequate choice of cells to be seeded on it. The introduction of stem cells, and the transdifferentiation procedures, into regenerative medicine opened a new era and created new challenges for modern biomaterials. They must not only fulfill the mechanical functions of a scaffold for implanted cells and represent the expected mechanical strength of the artificial tissue, but furthermore, they should also assure their survival and, if possible, affect their desired way of differentiation. This paper aims to review how modern biomaterials, including synthetic (i.e., polylactic acid, polyurethane, polyvinyl alcohol, polyethylene terephthalate, ceramics) and natural (i.e., silk fibroin, decellularized scaffolds), both non-biodegradable and biodegradable, could influence (tissue) stem cells fate, regulate and direct their differentiation into desired target somatic cells.


Assuntos
Materiais Biocompatíveis , Alicerces Teciduais , Materiais Biocompatíveis/farmacologia , Engenharia Tecidual/métodos , Medicina Regenerativa , Diferenciação Celular
4.
Analyst ; 146(15): 4865-4872, 2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34231570

RESUMO

Achieving efficient chiral discrimination by a convenient method remains a challenge in pharmaceutical and biotechnology industries. Our aim in this paper was to develop a dual-signaling enantioselective sensing strategy based on the competitive binding assay. A combination of ß-cyclodextrin (ß-CD) and methylene blue (MB) was used as an enantioselective discrimination probe to develop a straightforward electrochemical chiral sensor using the drug naproxen (R-and S-NaX) as the representative enantiomers. The principle relied on the difference between two enantiomers in the ability to replace a pre-binding redox probe, which in turn resulted in different dual signals for the two enantiomers. The applicability of the optimized procedure was demonstrated by the analysis of NaX enantiomers in the range of 0.4-6.0 µM. Featuring both signal-on and signal-off elements, the electrode presented significantly enhanced electrochemical activity with a low limit of detection (LOD) of 0.07 µM. We expect that our work will inspire interesting engineering strategies for developing novel enantioselective electrochemical sensors.


Assuntos
Técnicas Eletroquímicas , Azul de Metileno , Eletrodos , Limite de Detecção , Estereoisomerismo
5.
Mikrochim Acta ; 188(9): 305, 2021 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-34448045

RESUMO

Metal-organic frameworks (MOFs) have received extensive attention in adsorption applications owing to their high surface area. However, some MOFs do not perform well as the extraction medium when used under aqueous conditions. The low hydrostability of MOFs limits the practical application of these materials in solid-phase microextraction (SPME). Here, the fabrication of a water resistance SPME fiber coating is introduced based on the crystal violet (CV)-modified HKUST-1 framework on copper (Cu@HKUST-1@CV). The HKUST-1 was prepared by the in situ growth method, followed by post-synthetic modification of HKUST-1 with the CV layer. The preparation of the modified HKUST-1 was characterized by FESEM, XRD, FTIR, and DFT approaches. The prepared SPME coating was successfully employed for the quantification of anthracene (AN), as a model analyte, in water samples. The limit of detection was 0.8 ng mL-1. The developed method will open up a new door towards searching for promising materials in SPME applications.


Assuntos
Antracenos/isolamento & purificação , Violeta Genciana/química , Estruturas Metalorgânicas/química , Microextração em Fase Sólida/métodos , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Antracenos/química , Cobre/química , Água Potável/química , Limite de Detecção , Espectrometria de Fluorescência , Água/química , Poluentes Químicos da Água/química
6.
Int J Mol Sci ; 22(22)2021 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-34830361

RESUMO

The iontophoresis delivery of insulin (INS) remains a serious challenge due to the low permeability of the drug through the skin. This work aims to investigate the potential of water-soluble polypyrrole nanoparticles (WS-PPyNPs) as a drug donor matrix for controlled transdermal iontophoresis of INS. WS-PPyNPs have been prepared via a simple chemical polymerization in the presence of sodium dodecyl sulfate (SDS) as both dopant and the stabilizing agent. The synthesis of the soluble polymer was characterized using field emission scanning electron microscopy (FESEM), dynamic light scattering (DLS), fluorescence spectroscopy, and Fourier transform infrared (FT-IR) spectroscopy. The loading mechanism of INS onto the WS-PPyNPs is based on the fact that the drug molecules can be replaced with doped dodecyl sulfate. A two-compartment Franz-type diffusion cell was employed to study the effect of current density, formulation pH, INS concentration, and sodium chloride concentration on anodal iontophoresis (AIP) and cathodal iontophoresis (CIP) of INS across the rat skin. Both AIP and CIP delivery of INS using WS-PPyNPs were significantly increased compared to passive delivery. Furthermore, while the AIP experiment (60 min at 0.13 mA cm-2) show low cumulative drug permeation for INS (about 20.48 µg cm-2); the CIP stimulation exhibited a cumulative drug permeation of 68.29 µg cm-2. This improvement is due to the separation of positively charged WS-PPyNPs and negatively charged INS that has occurred in the presence of cathodal stimulation. The obtained results confirm the potential applicability of WS-PPyNPs as an effective approach in the development of controlled transdermal iontophoresis of INS.


Assuntos
Insulina/farmacologia , Iontoforese/métodos , Nanopartículas/química , Pele/efeitos dos fármacos , Administração Cutânea , Animais , Portadores de Fármacos/química , Portadores de Fármacos/farmacologia , Humanos , Microscopia Eletrônica de Varredura , Polímeros/química , Polímeros/farmacologia , Pirróis/química , Pirróis/farmacologia , Coelhos , Pele/ultraestrutura , Dodecilsulfato de Sódio/química , Dodecilsulfato de Sódio/farmacologia , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Água/química
7.
Int J Mol Sci ; 22(13)2021 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-34203268

RESUMO

Viral-associated respiratory infectious diseases are one of the most prominent subsets of respiratory failures, known as viral respiratory infections (VRI). VRIs are proceeded by an infection caused by viruses infecting the respiratory system. For the past 100 years, viral associated respiratory epidemics have been the most common cause of infectious disease worldwide. Due to several drawbacks of the current anti-viral treatments, such as drug resistance generation and non-targeting of viral proteins, the development of novel nanotherapeutic or nano-vaccine strategies can be considered essential. Due to their specific physical and biological properties, nanoparticles hold promising opportunities for both anti-viral treatments and vaccines against viral infections. Besides the specific physiological properties of the respiratory system, there is a significant demand for utilizing nano-designs in the production of vaccines or antiviral agents for airway-localized administration. SARS-CoV-2, as an immediate example of respiratory viruses, is an enveloped, positive-sense, single-stranded RNA virus belonging to the coronaviridae family. COVID-19 can lead to acute respiratory distress syndrome, similarly to other members of the coronaviridae. Hence, reviewing the current and past emerging nanotechnology-based medications on similar respiratory viral diseases can identify pathways towards generating novel SARS-CoV-2 nanotherapeutics and/or nano-vaccines.


Assuntos
Antivirais/química , Portadores de Fármacos/química , Nanomedicina , Infecções Respiratórias/patologia , Vacinas Virais/química , Viroses/patologia , Antivirais/uso terapêutico , COVID-19/imunologia , COVID-19/patologia , COVID-19/terapia , COVID-19/virologia , Humanos , Sistema Imunitário/metabolismo , Infecções Respiratórias/terapia , Infecções Respiratórias/virologia , SARS-CoV-2/isolamento & purificação , Vacinas Virais/administração & dosagem , Vacinas Virais/imunologia , Viroses/imunologia , Viroses/prevenção & controle , Viroses/terapia
8.
J Environ Manage ; 297: 113338, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34303937

RESUMO

In the present study, photodegradation of 4-chlorophenol (4-CP) using a step-scheme BiVO4/WO3 heterostructure under visible LED light irradiation (Vis LED) from aqueous solutions was investigated. The photocatalyst was synthesized through the hydrothermal process and characterized physically and chemically via X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), energy-dispersive X-ray (EDX), and Brunnauer-Emmett-Teller (BET) techniques. The effects of the operational parameters i.e., solution pH, contact time, nanocomposite dosage, and initial 4-CP concentration were evaluated. Results indicated that BiVO4/WO3/Vis LED process has higher efficiency in 4-CP degradation than BiVO4/Vis LED, WO3/Vis LED, and BiVO4/WO3 systems. At BiVO4/WO3 concentration of 0.125 g/L, initial pH of 7, and initial 4-CP concentration of 25 mg/L, complete degradation of 4-CP (>97%) was achieved in reaction time of 60 min. The phenol, chlorobenzene, catechol, 4-chlorocatechol, 5-chloro-1,2,4-benzenetriol, hydroquinone, hydroxyhydroquinone, p-benzoquinone, o-benzoquinone, formic acid, acetic acid, and oxalic acid were identified as the major intermediates of 4-CP degradation. In optimal condition, 67.5% and 88.5% of TOC and COD removal rates were obtained in 120 min contact time, respectively. The degradation of 4-CP was pseudo-first-order kinetics. Through the use of tert-Butyl alcohol (TBA) and ethylenediamine tetraacetic acid (EDTA) as radical scavengers, hydroxyl radicals and holes were identified as the main active species in photocatalytic degradation. Also, a tentative pathway for 4-CP degradation using the Vis LED/BiVO4/WO3 process was proposed.


Assuntos
Bismuto , Clorofenóis , Catálise , Fotólise
9.
Anal Chem ; 92(16): 11405-11412, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32687322

RESUMO

This work presents an effective strategy for the well-oriented immobilization of antibodies in which boronic acid is directly attached to the surface and with no need of the long and flexible spacer. A magnetic graphene nanoribbon-boronic-acid-based immunosensor was developed and tested for the impedimetric detection of lymphoma cancer cells, a blood cancer biomarker. Magnetic graphene nanoribbons (MGNRs) were modified with boronic acid (BA) to create a supporting matrix that is utilized by immobilizing anti-CD20 antibodies with good orientation. The prepared biosensing layer (MGNR/BA/Ab) with well-oriented antibodies was premixed into whole blood samples to interact with lymphoma cancer cell receptors. In the presence of target cell receptors, an immunocomplex was formed between anti-CD20 antibodies and lymphoma cancer cell receptors. Then, the biosensing layer was magnetically collected on a screen-printed carbon electrode (SPCE) and placed in a homemade electrochemical cell configuration to measure impedimetric signals. The fabrication steps of the immunosensor were characterized by various techniques, such as resonance light scattering, fluorescence, electrochemical impedance spectroscopy, and cyclic voltammetry. The assay is highly sensitive: the calculated limit of detection of lymphoma cancer cells was as low as 38 cells/mL, and the detection was linear from 100 to 1 000 000 cells/mL. The specificity of the immunosensor is also very high, and there is no interference effect with several potential interferents, such as the breast cancer (MCF-7), human embryonic kidney (HEK293), and leukemia (HL-60 and KCL-22) cell lines. The performance of the immunosensor for lymphoma cancer cells in clinical blood samples is consistent with that of commercial flow cytometric assays.


Assuntos
Anticorpos Imobilizados/imunologia , Biomarcadores Tumorais/sangue , Separação Celular/métodos , Imunoensaio/métodos , Linfoma/sangue , Nanotubos de Carbono/química , Anticorpos Imobilizados/química , Biomarcadores Tumorais/imunologia , Ácidos Borônicos/química , Linhagem Celular Tumoral , Técnicas Eletroquímicas , Células HEK293 , Humanos , Limite de Detecção , Linfoma/patologia , Fenômenos Magnéticos , Rituximab/química , Rituximab/imunologia
10.
Anal Bioanal Chem ; 412(7): 1629-1637, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31965245

RESUMO

A new magnetic molecularly imprinted nanofiber (MMIN) nanocomposite was prepared and used to the selective extraction of nilotinib. MMIN was constructed using a novel and general method including a combination of molecular imprinting and electrospinning technology. By electrospun precursor nanofibers containing polyacrylonitrile, Fe3O4 magnetic nanoparticles, and nilotinib as the template, molecularly imprinted nanofibers were produced with a mean diameter of 500 nm and lengths up to several millimeters. The microstructure and morphology of the prepared MMIN were thoroughly investigated using techniques such as X-ray diffraction (XRD) and scanning electron microscopy (SEM). The MMIN was then used to the extraction of nilotinib. The extracted nilotinib was re-extracted and determined spectrofluorimetrically at the excitation and emission wavelengths of 271 and 335 nm, respectively. The relation between fluorescence signal for the re-extracted solution and nilotinib concentration was linear in the range 0.01-10.0 mg L-1 (n = 9) and the RSD for the determination of 1.0 and 5.0 mg L-1 nilotinib 2.75% and 1.09% (n = 3), respectively. The detection limit of the method was obtained as 0.002 mg L-1 nilotinib. The results indicated that the proposed method can be successfully applied to the determination of nilotinib in human serum samples. Graphical abstract.


Assuntos
Magnetismo , Impressão Molecular , Nanofibras , Pirimidinas/isolamento & purificação , Resinas Acrílicas/química , Humanos , Limite de Detecção , Microscopia Eletrônica de Varredura , Pirimidinas/sangue , Reprodutibilidade dos Testes , Espectrometria de Fluorescência
11.
Anal Bioanal Chem ; 410(16): 3683-3691, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29627893

RESUMO

Sensitive detection of biomarkers will mean accurate and early diagnosis of diseases. A tissue plasminogen activator (tPA) has a crucial role in many cardiovascular diseases and it is related to many processes such as angiogenesis in cancer cells. Therefore, sensitive determination of tPA is important in diagnosis and clinical research. tPA monoclonal antibody was covalently attached onto single-wall carbon nanotubes (SWCNTs) using diimide-activated imidation coupling. Functionalized SWCNTs were immobilized onto a glassy carbon electrode and the modification process was investigated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), SEM, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). Cyclic voltammograms (CVs) in a scan rate of 100 mVs-1 was studied and comparisons were made between the modified glassy carbon electrodes (immobilized with antibodies) as a working electrode before and after the formation of tPA-antibody complex. Results of the SDS-PAGE demonstrated that the antibody was covalently and site directly attached to the SWCNTs. The fabricated biosensor provided a good linear response range from 0.1 to 1.0 ng mL-1 with a low detection limit of 0.026 ng mL-1. The immunosensor showed selectivity, reproducibility, good sensitivity, and acceptable stability. Satisfactory results were observed for early and sensitive determination of tPA in human serum samples. For the first time, such specific biosensor is currently being fabricated for tPA in our laboratories and successfully could determine tPA in myocardial infraction and breast cancer patients. Graphical abstract Fabricated biosensor for determination of tPA.


Assuntos
Anticorpos Imobilizados/química , Técnicas Biossensoriais/métodos , Neoplasias da Mama/sangue , Infarto do Miocárdio/sangue , Nanotubos de Carbono/química , Ativador de Plasminogênio Tecidual/sangue , Biomarcadores Tumorais/sangue , Neoplasias da Mama/diagnóstico , Detecção Precoce de Câncer/métodos , Técnicas Eletroquímicas/métodos , Feminino , Humanos , Imunoensaio/métodos , Limite de Detecção , Pessoa de Meia-Idade , Modelos Moleculares , Infarto do Miocárdio/diagnóstico , Nanotubos de Carbono/ultraestrutura , Reprodutibilidade dos Testes
12.
Anal Bioanal Chem ; 409(22): 5269-5278, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28667386

RESUMO

Vinblastine (VLB) is prescribed for a wide variety of cancers. Therefore, development of sensitive methods for early diagnosis is urgently required. In this work, a highly sensitive and label-free impedimetric biosensor was fabricated for the electrochemical detection of VLB. First, the gold nanoparticles (AuNPs) were electrodeposited on the surface of a glassy carbon electrode (GCE). 3-Mercaptopropionic acid (MPA) was self-assembled over the AuNPs. Then, tubulin (TUB), as a receptor, was covalently immobilized at the AuNPs/GCE surface via carbodiimide coupling reaction using N-(3 dimethylaminopropyl)-N'-ethyl carbodiimide (EDC) and N-hydroxy succinimide (NHS). The step-by-step modification process was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in the presence of a redox probe [Fe(CN)6]3-/4-. The VLB concentration was measured through the increase of impedance values in the corresponding specific binding of VLB and TUB. The increased electron-transfer resistance (R et) values were proportional to the value of VLB concentrations in the range of 0.4 to 65.0 nmol L-1 with a detection limit of 8.4 × 10-2 nmol L-1 (SN-1 = 3). The practical analytical performance of the proposed method was demonstrated by determination of VLB in plant extracts and human serum samples with satisfactory recoveries.


Assuntos
Técnicas Biossensoriais , Eletrodos , Vidro/química , Ouro/química , Nanopartículas Metálicas/química , Tubulina (Proteína)/química , Vimblastina/análise , Catharanthus/química , Técnicas Eletroquímicas/instrumentação , Humanos , Limite de Detecção , Microscopia Eletrônica de Varredura , Extratos Vegetais/química , Vimblastina/sangue , Vimblastina/química
13.
Anal Bioanal Chem ; 408(10): 2577-86, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26873212

RESUMO

A facile and effective approach of fabricating oxidized multiwalled carbon nanotube/glassy carbon electrode (OMWCNT/GCE) is herein reported. The OMWCNT/GCE was prepared by electrochemical oxidation method in basic media (0.5 mol L(-1) NaOH solution) and used as a sensor for simultaneous determination of dopamine (DA) and doxorubicin (DOX). Scanning electron microscopy, energy dispersive X-ray spectroscopy and cyclic voltammetry were used for characterization and performance study of the OMWCNT/GCE. The modified electrode exhibited good electrocatalytic properties toward the oxidation of DA and DOX. Peaks potential difference of 240 mV between DA and DOX was large enough to determine DA and DOX individually and simultaneously. Square wave voltammetry (SWV) was used for the simultaneous determination of DA and DOX in their binary mixture. Under the optimum conditions, the linear concentration dependences of SW peak current responses were observed for DA and DOX in the concentration ranges of 0.03-55 µmol L(-1) and 0.04-90 µmol L(-1), respectively. The detection limits (S/N = 3) were 8.5 × 10(-3) µmol L(-1), and 9.4 × 10(-3) µmol L(-1) for DA and DOX, respectively. The analytical utility of OMWCNT/GCE was also successfully demonstrated for the simultaneous determination of DA and DOX in human blood serum and urine samples. Graphical Abstract Fabrication of new oxidized multiwalled carbon nanotube/glassy carbon electrode for simultaneous determination of dopamine and doxorubicin.


Assuntos
Carbono/química , Dopamina/análise , Doxorrubicina/análise , Nanotubos de Carbono , Técnicas Eletroquímicas/métodos , Humanos , Concentração de Íons de Hidrogênio , Limite de Detecção , Microscopia Eletrônica de Varredura , Oxirredução , Reprodutibilidade dos Testes
14.
Luminescence ; 30(5): 576-82, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25377137

RESUMO

A sensitive spectrofluorimetric method using constant-energy synchronous fluorescence technique is proposed for the determination of human albumin without separation. In this method, no reagent was used for enhancement of the fluorescence signal of albumin in the solution. Effects of some parameters, such as energy difference between excitation and emission monochromators (ΔE), emission and excitation slit widths and scan rate of wavelength were studied and the optimum conditions were established. For this purpose factorial design and response surface method were employed for optimization of the effective parameters on the fluorescence signal. The results showed that the scan rate of the wavelength has no significant effect on the analytical signal. The calibration curve was linear in the range 0.1-220.0 µg mL(-1) of albumin with a detection limit of 7.0 × 10(-3) µg mL(-1). The relative standard deviations (RSD) for six replicate measurements of albumin were calculated as 2.2%, 1.7% and 1.3% for 0.5, 10.0 and 100.0 µg mL(-1) albumin, respectively. Furthermore the proposed method has been employed for the determination of albumin in human serum and urine samples.


Assuntos
Albumina Sérica/análise , Espectrometria de Fluorescência/métodos , Albuminúria/diagnóstico , Calibragem , Humanos , Limite de Detecção
15.
Talanta ; 274: 126041, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38581854

RESUMO

This paper presents the development and optimization of a cost-effective paper electrochemical sensor for the detection of TNT using Fe3O4-Au core-shell nanoparticles modified with cysteamine (Fe3O4@Au/CA). The sensor was constructed by modifying a graphite paste with the aforementioned nanoparticles, which facilitated the formation of a Meisenheimer complex between cysteamine and TNT as an electron donor and an electron acceptor, respectively. The central composite design was employed to optimize four key parameters pH, modifier percentage, contact time, and buffer type to enhance the performance of the sensor. The detection limit was found to be 0.5 nM of TNT, while the linear range of the electrode response spanned from 0.002 µM to 10 µM. The simplicity and low cost of the sensor make it highly attractive for practical applications, particularly in scenarios where rapid and on-site TNT detection is required.

16.
Sci Rep ; 14(1): 13594, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38867065

RESUMO

This research presents a compact portable electronic gas sensor that can be monitored through a smartphone application. The smart sensor utilizes three state-of-the-art sensors. The sensors integrate an ESP8266 microcontroller within the same device. This facilitates their integration with the electronics and enhances their performance. Herein, primarily focuses on utilizing the sensor to detect carbon monoxide. This article outlines the fabrication process of a gas sensor utilizing a P-N heterojunction, eliminating the need for a binder. The sensor consists of CuO/copper foam nanowires and hierarchical In2O3. In order to verify the system's functionality, it underwent testing with various levels of CO concentrations (10-900 ppm), including particular tests designed to examine the device's performance in different humidity and temperature circumstances. A mobile application for the provision of monitoring services has been developed at last. To process the information obtained from the gas sensor, an algorithm has been constructed, trained, and integrated into a smartphone for this purpose. This research demonstrated that a smartphone-coupled gas sensor is a viable system for real-time monitoring and the detection of CO gas.

17.
Sci Rep ; 14(1): 2480, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38291089

RESUMO

2,4-Dinitrotoluene (2,4-DNT) as a priority and hazardous pollutant, is widely used in industrial and military activities. In this study the synergistic effect of Fe-RGO-BiVO4 nanocomposite in a non-thermal dielectric barrier discharge plasma reactor (NTP-DBD) for degrading 2,4-DNT was evaluated. Preparation of the Fe-RGO-BiVO4 nanocomposite was done by a stepwise chemical method depositing Fe and reduced graphene oxide (RGO) on BiVO4. Field emission scanning electron microscopy (FESEM), X-ray diffraction analysis (XRD), UV-vis diffuse reflectance spectra (DRS), and energy-dispersive X-ray spectroscopy mapping (EDS-mapping) validated the satisfactory synthesis of Fe-RGO-BiVO4. To find the optimal conditions and to determine the interaction of model parameters, a central composite design (RSM-CCD) had been employed. 2,4 DNT can be completely degraded at: initial 2,4-DNT concentration of 40 mg L-1, Fe-RGO-BiVO4 dosage of 0.75 g L-1, applied voltage of 21kV, reaction time of 30 min and pH equal to 7, while the single plasma process reached a degradation efficiency of 67%. The removal efficiency of chemical oxygen demand (COD) and total organic carbon (TOC) were 90.62% and 88.02% at 30 min contact time, respectively. Results also indicated that average oxidation state (AOS) and carbon oxidation state (COS) were enhanced in the catalytic NTP-DBD process, which demonstrate the effectiveness of proposed process for facilitating biodegradability of 2,4-DNT.

18.
Sci Rep ; 14(1): 11526, 2024 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-38773136

RESUMO

This paper reports on the development of a flexible-wearable potentiometric sensor for real-time monitoring of sodium ion (Na+), potassium ion (K+), and pH in human sweat. Na0.44MnO2, polyaniline, and K2Co[Fe(CN)6] were used as sensing materials for Na+, H+ and K+ monitoring, respectively. The simultaneous potentiometric Na+, K+, and pH sensing were carried out by the developed sensor, which enables signal collection and transmission in real-time to the smartphone via a Wi-Fi access point. Then, the potentiometric responses were evaluated by a designed android application. Na+, K+, and pH sensors illustrated high sensitivity (59.7 ± 0.8 mV/decade for Na+, 57.8 ± 0.9 mV/decade for K+, and 54.7 ± 0.6 mV/pH for pH), excellent stability, and good batch-to-batch reproducibility. The results of on-body experiments demonstrated that the proposed platform is capable of real-time monitoring of the investigated ions.


Assuntos
Potássio , Potenciometria , Sódio , Suor , Dispositivos Eletrônicos Vestíveis , Humanos , Concentração de Íons de Hidrogênio , Potenciometria/métodos , Potenciometria/instrumentação , Sódio/análise , Suor/química , Potássio/análise , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Tecnologia sem Fio/instrumentação , Smartphone , Reprodutibilidade dos Testes
19.
Analyst ; 138(16): 4542-9, 2013 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-23739162

RESUMO

A drug imprinted polymer based on suspension polymerization on magnetic multi-walled carbon nanotubes (MIPMCNTs) was prepared with a synthesized amidoamine as the functional monomer, ethylene glycol dimethacrylate as the cross-linker, naproxen (NAP) as the template and ammonium persulfate as the initiator. The MIPMCNTs were characterized by TEM, FT-IR and XRD measurements. The prepared magnetic adsorbent can be well dispersed in aqueous media and can be easily separated magnetically from the medium after loading with NAP. All the aspects influencing the adsorption (extraction time, adsorbent dosage and pH) and desorption (desorption time and desorption solvent) of the analyte on the MIPMCNTs have been investigated. The extracted NAP could be easily desorbed with a mixture of methanol/sodium hydroxide aqueous solution and determined spectrofluorometrically at λem = 353 nm (λex = 271 nm). A linear dynamic range was established from 4.0 to 40.0 ng mL⁻¹ of NAP and the limit of detection (LOD) was found to be 2.0 ng mL⁻¹. In addition, the equilibrium adsorption data of NAP by imprinted polymer were analyzed by Langmuir and Freundlich isotherm models. The developed method was utilized for the determination of NAP in human urine samples with satisfactory results.


Assuntos
Anti-Inflamatórios não Esteroides/urina , Nanotubos de Carbono/química , Naproxeno/urina , Polímeros/química , Extração em Fase Sólida/métodos , Humanos , Magnetismo , Espectrometria de Fluorescência/métodos , Difração de Raios X
20.
Sci Rep ; 13(1): 11381, 2023 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-37452101

RESUMO

Electrochemical impedance spectroscopy (EIS) is a highly effective technique for studying the surface of electrodes in great detail. EIS-based electrochemical sensors have been widely reported, which measure the charge transfer resistance (Rct) of redox probes on electrode surfaces to monitor the binding of target molecules. One of the protective drugs against hemorrhagic cystitis caused by oxazaphosphorine chemotherapy drugs such as ifosfamide, cyclophosphamide and trophosphamide is Mesna (sodium salt of 2-mercaptoethanesulfonate). The increase in the use of Mesna due to the high consumption of anti-cancer drugs, the determination of this drug in biological samples is of particular importance. So far, no electrochemical method has been reported to measure Mesna. In this research, a novel impedimetric sensor based on a glassy carbon electrode (GCE) modified with oxidized multiwalled carbon nanotubes (MWCNTs)/gold nanoparticle (AuNPs) (denoted as Au NPs/MWCNTs/GCE) for impedimetric determination of Mesna anticancer drug was developed. The modified electrode materials were characterized by field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX), and EIS. The electrochemical behavior of Mesna at the surface of Au NPs/MWCNTs/GCE was studied by an impedimetric method. The detection mechanism of Mesna using the proposed impedimetric sensor relied on the increase in the Rct value of [Fe (CN)6]3-/4- as an electrochemical probe in the presence of Mesna compared to the absence of Mesna as the analyte. Under the optimum condition, which covered two linear dynamic ranges from 0.06 nmol L-1 to 1.0 nmol L-1 and 1.0 nmol L-1 to 130.0 µmol L-1, respectively. The detection limit was 0.02 nmol L-1. Finally, the performance of the proposed sensor was investigated for Mesna electrochemical detection in biological samples.


Assuntos
Antineoplásicos , Nanopartículas Metálicas , Nanotubos de Carbono , Nanopartículas Metálicas/química , Mesna , Ouro/química , Nanotubos de Carbono/química , Eletrodos , Técnicas Eletroquímicas , Limite de Detecção
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