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1.
Sensors (Basel) ; 21(5)2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33668211

RESUMO

The electrochemical-based detection of uric acid (UA) is widely used for diagnostic purposes. However, various interfering species such as ascorbic acid, dopamine, and glucose can affect electrochemical signals, and hence there is an outstanding need to develop improved sensing platforms to detect UA with high selectivity. Herein, we report a pentagonal mediator-based non-enzymatic electrochemical biosensing platform to selectively measure UA in the presence of interfering species. The working electrode was fabricated by electrodepositing polymerized 1-vinylimidazole (PVI), which has an imidazole ligand, onto indium tin oxide (ITO), and then conjugating nickel ions to the PVI-coated ITO electrode. Electrode performance was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements and integrated together with pentacyanoammineferrate, which can bind to the amine groups of UA and function as an electron transferring mediator. The experimental results showed a wide linear range of UA concentration-dependent responses and the multi-potential step (MPS) technique facilitated selective detection of UA in the presence of physiologically relevant interfering species. Altogether, these findings support that pentacyanoammineferrate-based non-enzymatic electrodes are suitable biosensing platforms for the selective measurement of UA, and such approaches could potentially be extended to other bioanalytes as well.


Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , Ferrocianetos/química , Ácido Úrico/análise , Eletrodos
2.
Int J Mol Sci ; 22(2)2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33467391

RESUMO

Prussian blue (PB) and PB analogues (PBA) are coordination network materials that present important similarities with zeolites concretely with their ability of adsorbing cations. Depending on the conditions of preparation, which is cheap and easy, PB can be classified into soluble PB and insoluble PB. The zeolitic-like properties are mainly inherent to insoluble form. This form presents some defects in its cubic lattice resulting in an open structure. The vacancies make PB capable of taking up and trapping ions or molecules into the lattice. Important adsorption characteristics of PB are a high specific area (370 m2 g-1 determined according the BET theory), uniform pore diameter, and large pore width. PB has numerous applications in many scientific and technological fields. PB are assembled into nanoparticles that, due to their biosafety and biocompatibility, can be used for biomedical applications. PB and PBA have been shown to be excellent sorbents of radioactive cesium and radioactive and nonradioactive thallium. Other cations adsorbed by PB are K+, Na+, NH4+, and some divalent cations. PB can also capture gaseous molecules, hydrocarbons, and even luminescent molecules such as 2-aminoanthracene. As the main adsorptive application of PB is the selective removal of cations from the environment, it is important to easily separate the sorbent of the purified solution. To facilitate this, PB is encapsulated into a polymer or coats a support, sometimes magnetic particles. Finally, is remarkable to point out that PB can be recycled and the adsorbed material can be recovered.


Assuntos
Césio/química , Corantes/química , Ferrocianetos/química , Poluentes Químicos da Água/química , Zeolitas/química , Adsorção , Materiais Biocompatíveis/química , Íons , Cinética , Solubilidade
3.
Nat Chem Biol ; 17(3): 246-253, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33432236

RESUMO

DNA has been the predominant information storage medium for biology and holds great promise as a next-generation high-density data medium in the digital era. Currently, the vast majority of DNA-based data storage approaches rely on in vitro DNA synthesis. As such, there are limited methods to encode digital data into the chromosomes of living cells in a single step. Here, we describe a new electrogenetic framework for direct storage of digital data in living cells. Using an engineered redox-responsive CRISPR adaptation system, we encoded binary data in 3-bit units into CRISPR arrays of bacterial cells by electrical stimulation. We demonstrate multiplex data encoding into barcoded cell populations to yield meaningful information storage and capacity up to 72 bits, which can be maintained over many generations in natural open environments. This work establishes a direct digital-to-biological data storage framework and advances our capacity for information exchange between silicon- and carbon-based entities.


Assuntos
Engenharia Celular/métodos , DNA/genética , Técnicas Eletroquímicas , Elétrons , Escherichia coli/genética , Armazenamento e Recuperação da Informação/métodos , Sequência de Bases , Sistemas CRISPR-Cas , Carbono/química , DNA/classificação , DNA/metabolismo , Eletricidade , Escherichia coli/metabolismo , Ferrocianetos/química , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Oxirredução , Análise de Sequência de DNA , Silício/química
4.
Food Chem ; 339: 127881, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32866703

RESUMO

A novel and rapid Electrochemical Immunosensing platform was developed for the direct sensing of antibody human immuno globulin gamma (IgG) interaction with virulence factor of S. aureus, staphylococcal protein A (SpA) in the presence of electroactive redox couple ferri/ferro cyanide (K3/K4[Fe(CN)6]). The receptor SpA was attached to BioPE-DOTAP binary lipid bilayer tethered on alkane thiol molecular cushions. Atomic force microscopy (AFM), High-resolution transmission electron microscope (TEM), Fourier-transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS) techniques were used to study the molecular interactions. The AFM images showed array like formation of BioPE-DOTAP on the monolayer surface. The IgG sensor showed a linear range from 10-21 M to 10-16 M.


Assuntos
Técnicas Eletroquímicas/métodos , Imunoglobulina G/metabolismo , Proteína Estafilocócica A/metabolismo , Eletrodos , Ferricianetos/química , Ferrocianetos/química , Ouro/química , Humanos , Imunoglobulina G/química , Microscopia de Força Atômica , Oxirredução , Ligação Proteica , Proteína Estafilocócica A/química
5.
Ultrason Sonochem ; 70: 105317, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32891882

RESUMO

In healthcare facilities, environmental microbes are responsible for numerous infections leading to patient's health complications and even death. The detection of the pathogens present on contaminated surfaces is crucial, although not always possible with current microbial detection technologies requiring sample collection and transfer to the laboratory. Based on a simple sonochemical coating process, smart hospital fabrics with the capacity to detect live bacteria by a simple change of colour are presented here. Prussian Blue nanoparticles (PB-NPs) are sonochemically coated on polyester-cotton textiles in a single-step requiring 15 min. The presence of PB-NPs confers the textile with an intensive blue colour and with bacterial-sensing capacity. Live bacteria in the textile metabolize PB-NPs and reduce them to colourless Prussian White (PW), enabling in situ detection of bacterial presence in less than 6 h with the bare eye (complete colour change requires 40 h). The smart textile is sensitive to both Gram-positive and Gram-negative bacteria, responsible for most nosocomial infections. The redox reaction is completely reversible and the textile recovers its initial blue colour by re-oxidation with environmental oxygen, enabling its re-use. Due to its simplicity and versatility, the current technology can be employed in different types of materials for control and prevention of microbial infections in hospitals, industries, schools and at home.


Assuntos
Ferrocianetos/química , Bactérias Gram-Negativas/isolamento & purificação , Bactérias Gram-Positivas/isolamento & purificação , Sonicação/métodos , Têxteis , Cor , Hospitais
6.
Int J Nanomedicine ; 15: 5165-5177, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32764943

RESUMO

Background: The integration of NIR photothermal therapy and chemotherapy is considered as a promising technique for future cancer therapy. Hollow Prussian nanospheres have attracted much attention due to excellent near-infrared photothermal conversion effect and drug-loading capability within an empty cavity. However, to date, the hollow Prussian nanospheres have been prepared by a complex procedure or in organic media, and their shell thickness and size cannot be controlled. Thus, a simple and controllable route is highly desirable to synthesize hollow Prussian nanospheres with controllable parameters. Materials and Methods: Here, in our designed synthesis route, the traditional FeCl3 precursor was replaced with Fe2O3 nanospheres, and then the Prussian blue (PB) nanoparticles were engineered into hollow-structured PB (HPB) nanospheres through an interface reaction, where the Fe2O3 colloidal template provides Fe3+ ions. The reaction mechanism and control factors of HPB nanospheres were systematically investigated. Both in vitro and in vivo biological effects of the as-synthesized HPB nanospheres were evaluated in detail. Results: Through systematical experiments, a solvent-mediated interface reaction mechanism was put forward, and the parameters of HPB nanospheres could be easily adjusted by growth time and template size under optimal water and ethanol ratio. The in vitro tests show the rapid and remarkable photothermal effects of the as-prepared HPB nanospheres under NIR laser irradiation (808 nm). Meanwhile, HPB nanospheres also demonstrated a high DOX loading capacity of 440 mg g-1 as a drug carrier, and the release of the drug can be regulated by the heat from PB shell under the exposure of an NIR laser. The in vivo experiments confirmed the outstanding performance of HPB nanospheres in photothermal/chemo-synergistic therapy of cancer. Conclusion: A solvent-mediated template route was developed to synthesize hollow Prussian blue (HPB) nanospheres in a simple and controllable way. The in vitro and in vivo results demonstrate the as-synthesized HPB nanospheres as a promising candidate due to their low toxicity and high efficiency for cancer therapy.


Assuntos
Portadores de Fármacos/química , Ferrocianetos/química , Nanosferas/química , Fototerapia/métodos , Terapia Combinada , Doxorrubicina/química , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Compostos Férricos/química , Humanos , Hipertermia Induzida
7.
Food Chem ; 329: 127224, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32516716

RESUMO

To overcome the drawbacks of antibody labeling dependence and single-readout system in the conventional lateral flow immunoassays (LFIAs) as well as the non-targeted combination of new capture agents reported recently for pathogen detection, in this work, a multi-readout and label-free LFIA was proposed for rapid detection of Escherichia coli O157:H7 (E. coli O157:H7) based on a nanozyme-bacteria-antibody sandwich pattern. A type of functional nanozyme-mannose modified Prussian blue (man-PB), was introduced as the recognition agent as well as signal indicator. Apart from original signal intensity on the T-line, the peroxidase-like catalytic activity-driven generation of colorimetric signal could be used as another format of quantitation. Importantly, such LFIA could exhibit excellent performance for target pathogens detection separately with a quantitative range of 102-108 cfu·mL-1 and a low detection limit of 102 cfu·mL-1 based on different readout formats, indicating the application potential of the proposed LFIA in real samples.


Assuntos
Escherichia coli O157/isolamento & purificação , Imunoensaio , Nanopartículas/química , Anticorpos Antibacterianos/química , Anticorpos Antibacterianos/imunologia , Catálise , Colorimetria , Escherichia coli O157/imunologia , Ferrocianetos/química , Microbiologia de Alimentos , Limite de Detecção , Manose/química , Nanopartículas/metabolismo
8.
Inorg Chem ; 59(7): 4567-4575, 2020 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-32149510

RESUMO

We report the postsynthetic functionalization of Prussian blue (PB) nanoparticles by two different luminophores (2-aminoanthracene and rhodamine B). We show that the photoluminescence properties of the fluorophores are modified by a confinement effect upon adsorption and demonstrate that such multifunctional nanosized systems could be used for in vitro imaging.


Assuntos
Antracenos/química , Ferrocianetos/química , Corantes Fluorescentes/química , Nanopartículas/química , Rodaminas/química , Adsorção , Linhagem Celular Tumoral , Corantes Fluorescentes/síntese química , Humanos , Microscopia de Fluorescência
9.
Chemosphere ; 250: 126262, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32114342

RESUMO

As an attractive alternative to radioactive cesium removal, we introduced an adsorptive filtration method using a composite membrane consisting of potassium copper hexacyanoferrate (KCuHCF) and graphene-based support. Polyethyleneimine-grafted reduced graphene oxide (PEI-rGO), used as an immobilizing matrix, was effective not only in distributing KCuHCF inside the composite with the aid of abundant amino-functionality, but also in achieving high water flux by increasing the interlayer spacing of the laminar membrane structure. Due to the rapid and selective cesium adsorption properties of KCuHCF, the fabricated membrane was found to be effective in achieving complete removal of cesium ions under a high flux (over 500 L m-2 h-1), which is difficult in a conventional membrane utilizing the molecular sieving effect. This approach offers strong potential in the field of elimination of radionuclides that require rapid and complete decontamination.


Assuntos
Césio/química , Ferrocianetos/química , Grafite/química , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Poluentes Químicos da Água/química , Adsorção , Cobre/química , Filtração , Polietilenoimina/química , Potássio , Água
10.
Biosensors (Basel) ; 10(3)2020 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-32183297

RESUMO

In this article, a highly sensitive label-free immunosensor based on a graphene oxide (GO)/Fe3O4/Prussian blue (PB) nanocomposite modified electrode was developed for the determination of human hepatitis B surface antigen (HBsAg). In this electrochemical immunoassay system, PB was used as a redox probe, while GO/Fe3O4/PB nanocomposites and AuNPs were prepared and coated on screen-printed electrodes to enhance the detection sensitivity and to immobilize the hepatitis B surface antibody (HBsAb). The immunosensor was fabricated based on the principle that the decrease in peak currents of PB is proportional to the concentration of HBsAg captured on the modified immunosensor. The experimental results revealed that the immunosensor exhibited a sensitive response to HBsAg in the range of 0.5 pg·mL-1 to 200 ng·mL-1, and with a low detection limit of 0.166 pg·mL-1 (S/N = 3). Furthermore, the proposed immunosensor was used to detect several clinical serum samples with acceptable results, and it also showed good reproducibility, selectivity and stability, which may have a promising potential application in clinical immunoassays.


Assuntos
Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Ferrocianetos/química , Grafite/química , Antígenos de Superfície da Hepatite B/química , Imunoensaio/métodos , Nanopartículas Metálicas/química , Nanocompostos/química , Humanos
11.
Anal Bioanal Chem ; 412(8): 1933-1946, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32076788

RESUMO

Biogenic amine biosensors, based on screen-printed carbon electrodes (SPCE) modified with Prussian blue (PB) and indium tin oxide nanoparticles (ITONP), are reported. PB/ITONP-modified SPCE was further modified with diamine oxidase (DAO) or monoamine oxidase (MAO) enzymes to construct the biosensors. The morphology of the modified electrodes was studied by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and atomic force microscopy (AFM). Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to enlighten the electrochemical properties of the modified electrodes at each step of biosensor fabrication. Electrode surface composition and experimental conditions were optimized and analytical performance characteristics of the biosensors were studied. Several biogenic amines were tested and both biosensors responded to histamine, putrescine and cadaverine. DAO/ITONP/PB/SPCE biosensor exhibited the highest response to histamine 6.0 × 10-6-6.9 × 10-4 M with a sensitivity of 1.84 µA mM-1. On the other hand, the highest sensitivity was obtained for cadaverine with the MAO/ITONP/PB/SPCE biosensor. The analytical utility of the presented biosensors were illustrated by the determination of cadaverine and histamine in cheese sample.


Assuntos
Amina Oxidase (contendo Cobre)/química , Aminas Biogênicas/análise , Técnicas Eletroquímicas/instrumentação , Eletrodos , Ferrocianetos/química , Nanopartículas Metálicas/química , Monoaminoxidase/química , Compostos de Estanho/química , Técnicas Biossensoriais
12.
Biomater Sci ; 8(7): 1830-1839, 2020 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-32057056

RESUMO

The development of highly effective and minimally invasive approaches for cancer treatment is the ultimate goal. Herein, an injectable hybrid hydrogel as a biomimetic cascade bioreactor is designed for combination antitumor therapy by providing spatiotemporally-controlled and long-term delivery of therapeutic agents. This hybrid nanozyme@hydrogel (hPB@gellan) is doped with Prussian blue (PB) nanoparticles via the in situ nanoprecipitation method in the polysaccharide gellan matrix. The obtained PB nanoparticles have a small size of 10 nm and play dual roles as a photothermal agent with a photothermal conversion efficiency of 59.6% and as a nanozyme to decompose hydrogen peroxide into oxygen. By incorporating glucose oxidase (GOD) into the hybrid hydrogel, a cascade bioreactor is formed for PB-promoted glucose consumption. Owing to its shear-thinning and self-recovery properties, the hybrid hydrogel is locally administered into tumors, and shows long-term resistance against body clearance and metabolism. The in vivo antitumor results demonstrate that the tumors in the group of combined photothermal and starvation therapy (GOD/hPB@gellan + NIR) are greatly eliminated with a tumor suppression rate of 99.7% 22 days after the treatment. The outstanding antitumor performance is attributed to the main attack by NIR-triggered hyperthermia and the holding attack by GOD-mediated starvation from the catalytic bioreactor of the hybrid hydrogel. Taking into consideration the advantages of biosafety, simple synthetic approaches and facile manipulation in treatment, the hybrid hydrogel has great potential for clinical translation.


Assuntos
Neoplasias da Mama/terapia , Ferrocianetos/química , Glucose Oxidase/administração & dosagem , Peróxido de Hidrogênio/metabolismo , Polissacarídeos Bacterianos/química , Animais , Materiais Biomiméticos , Reatores Biológicos , Neoplasias da Mama/metabolismo , Terapia Combinada , Preparações de Ação Retardada , Sinergismo Farmacológico , Feminino , Glucose Oxidase/química , Glucose Oxidase/farmacologia , Hidrogéis/química , Hipertermia Induzida , Camundongos , Nanopartículas/química , Fototerapia , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Biomater Sci ; 8(7): 1981-1995, 2020 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-32068203

RESUMO

Improving the generation of reactive oxygen species (ROS) while consuming glutathione (GSH) is the main method for amplifying intracellular oxidative stress. However, in previous studies, it was normally necessary to combine two or more materials to achieve the effect of destroying the intracellular redox homeostasis. This made the preparation process relatively complicated. Herein, we designed ultra-small bismuth sulfide quantum dot (Bi2S3 QD)-doped hollow mesoporous Prussian blue (HMPB) (HMPB/Bi2S3) nanocubes for amplified tumor oxidative stress to augment photo-/radiotherapy. In addition to being photothermal materials, Prussian blue can be used as both a catalyst for the Fenton reaction and a consumer of GSH due to the multivalent state of iron. Ferrous ions (Fe(ii)) can produce toxic ROS-hydroxyl radicals (˙OH) with abundant hydrogen peroxide in the tumor cells by the Fenton reaction. Meanwhile, ferric ions (Fe(iii)) can oxidize the intracellular GSH to GSSG, thus depleting the concentration of GSH inside tumors. As a result, oxidative stress imbalance could be induced by the reversible redox property of Fe(ii/iii), thereby causing DNA damage and increasing the cell membrane permeability to realize enhanced photo-/radiotherapy. As a sensitizer for radiotherapy, ultra-small Bi2S3 QDs (3-5 nm) are doped in HMPB, thus improving the therapeutic effect by prolonging blood circulation and reducing systemic toxicity via kidney metabolism. Therefore, such a reversible HMPB/Bi2S3 nanocube is a promising therapeutic agent for amplified tumor oxidative stress to augment photo-/radiotherapy, which might show further applications in nanomedical science.


Assuntos
Bismuto/química , Neoplasias da Mama/terapia , Ferrocianetos/química , Ferro/química , Fototerapia/métodos , Radioterapia/métodos , Sulfetos/química , Animais , Neoplasias da Mama/metabolismo , Feminino , Humanos , Peróxido de Hidrogênio/metabolismo , Células MCF-7 , Camundongos , Nanoestruturas , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/efeitos da radiação , Pontos Quânticos , Espécies Reativas de Oxigênio/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Chemosphere ; 244: 125589, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32050353

RESUMO

Radioactive Cs ions are extremely harmful to the human body, causing cancers and other diseases. Treatments were performed on radioactive Cs present in wastewater after use in industrial or medical fields. Prussian blue (PB) has been widely used for the removal of Cs ions from water but its colloidal structure hinders reuse, making it problematic for practical use. To solve this problem, we used a commercial macroporous polymer resin as a PB matrix. To provide an efficient anchor for PB, the surface of the polymer resin was decorated with sodium dodecylbenzenesulfonate to produce a negatively charged surface. The successful chemical binding between the polymer resin and PB prevented leakage of the latter during adsorption and crosslinked structure of the matrix provided regeneration of the adsorbent. The adsorbent maintained its removal efficiency after five repeats of the regeneration process. The PB-based, Cs ion-exchange resin showed excellent selectivity toward Cs ions and good reusability, maintaining its high adsorption capacity.


Assuntos
Benzenossulfonatos/química , Césio/química , Ferrocianetos/química , Resinas de Troca Iônica/química , Poluentes Químicos da Água/química , Adsorção , Humanos , Águas Residuárias/química , Purificação da Água
15.
Anal Bioanal Chem ; 412(8): 1769-1784, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32043201

RESUMO

Simultaneous speciation of benzenediol isomers (BDIs), 1,2-benzenediol (catechol, CC), 1,3-benzenediol (resorcinol, RS), and 1,4-benzenediol (hydroquinone, HQ), was investigated by differential pulse voltammetry (DPV) using a graphite paste electrode (GPE) modified with Prussian blue-polyaniline nanocomposite. The modified GPE showed good stability, sensitivity, and selectivity properties for all the three BDIs. Prussian blue-doped nanosized polyaniline (PBNS-PANI) was synthesized first by using mechanochemical reactions between aniline and ferric chloride hexahydrate as the oxidants and then followed by the addition of potassium hexacyanoferrate(II) in a solid-state and template-free technique. The material was characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). The DPV measurements are performed in phosphate electrolyte solution with pH 4.0 at a potential range of - 0.1 to 1.0 V. The proposed modified electrode displayed a strong, stable, and continuous three well-separated oxidation peaks towards electrooxidation at potentials 0.20, 0.31, and 0.76 V for HQ, CC, and RS, respectively. The calibration curves were linear from 1 to 350.5 µM for both HQ and CC, while for RS, it was from 2 to 350.5 µM. The limit of detection was determined to be 0.18, 0.01, and 0.02 µM for HQ, CC, and RS, respectively. The analytical performance of the PBNS-PANI/GPE has been evaluated for simultaneous determination of HQ, CC, and RS in creek water, commercial hair dye, and skin whitening cream samples with satisfactory recoveries between 90 and 106%. Overall, we demonstrated that the presence of NS-PANI and PB resulted in a large redox-active surface area that enabled a promising analytical platform for simultaneous detection of BDIs. Graphical abstract.


Assuntos
Compostos de Anilina/química , Derivados de Benzeno/análise , Ferrocianetos/química , Nanoestruturas/química , Derivados de Benzeno/química , Calibragem , Eletrodos , Humanos , Concentração de Íons de Hidrogênio , Isomerismo , Cinética , Limite de Detecção , Espectroscopia de Infravermelho com Transformada de Fourier
16.
Mikrochim Acta ; 187(1): 94, 2020 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-31902014

RESUMO

Poly(3,4-ethylenedioxythiophene) (PEDOT) films were electrodeposited by cyclic voltammetry on a glassy carbon electrode (GCE) in aqueous solution. Three kinds of supporting electrolytes were used, viz. graphene oxide (GO), phosphate buffered saline (PBS), and GO in PBS, respectively. The surface morphology of the modified electrodes was characterized by scanning electron microscopy. The electrochemical performance of the modified electrodes was investigated by cyclic voltammetry and electrochemical impedance spectroscopy by using the hexacyanoferrate redox system. The results demonstrate that the PEDOT-GO/GCE, which was electropolymerized in aqueous solutions containing EDOT and GO, shows the best electrochemical activities compared with other modified electrodes. The electrochemical behaviors of ascorbic acid (AA), dopamine (DA) and uric acid (UA) were investigated by cyclic voltammetry. The PEDOT-GO/GCE exhibits enhanced electrocatalytic activities towards these important biomolecules. Under physiological pH conditions and in the mixed system of AA, DA and UA, the modified GCE exhibits the following figures of merit: (a) a linear voltammetric response in the concentration ranges of 100-1000 µM for AA, 6.0-200 µM for DA, and 40-240 µM for UA; (b) well separated oxidation peaks near 31, 213 and 342 mV (vs. saturated Ag/AgCl) for AA, DA and UA, respectively; and (c) detection of limits (at S/N = 3) of 20, 2.0 and 10 µM. The results demonstrate that GO, based on its relatively large number of anionic sites, can be used as the sole weak electrolyte and charge balance dopant for the preparation of functionally doped conducting polymers by electrodeposition. Graphical abstractSchematic representation of a nanostructure composed of hybrid conducting polymer PEDOT-GO nanocomposites, and its application to simultaneous determination of ascorbic acid, dopamine and uric acid.


Assuntos
Ácido Ascórbico/análise , Dopamina/análise , Técnicas Eletroquímicas/métodos , Ácido Úrico/análise , Compostos Bicíclicos Heterocíclicos com Pontes , Técnicas Eletroquímicas/normas , Eletrodos , Galvanoplastia/métodos , Ferrocianetos/química , Grafite , Oxirredução , Polímeros
17.
Anal Chim Acta ; 1097: 169-175, 2020 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-31910957

RESUMO

In this work, a label-free electrochemical immunosensor was developed for the detection of procalcitonin (PCT), using toluidine blue functionalized NiFe Prussian-blue analog nanocubes (NiFe PBA nanocubes@TB) as a signal amplifier. NiFe PBA nanocubes was synthesized by a simple and efficient self-templating method in this work. NiFe PBA nanocubes with open-framework construction not only provides a larger specific area to load a mass of antibodies but produces an excellent signal without adding extra reaction reagent. Besides, the electrochemical performance of NiFe PBA nanocubes can be enhanced after functionalized with TB. The developed immunosensor exhibited favorable performance for PCT detection with a linear range from 0.001 to 25 ng mL-1 and a detection limit of 3 × 10-4 ng mL-1. Moreover, the immunosensor with acceptable reproducibility, selectivity, and stability may provide a new strategy in the clinical detection of PCT.


Assuntos
Ferrocianetos/química , Imunoensaio , Ferro/química , Nanocompostos/química , Níquel/química , Pró-Calcitonina/análise , Cloreto de Tolônio/química , Técnicas Biossensoriais , Técnicas Eletroquímicas , Humanos , Tamanho da Partícula , Propriedades de Superfície
18.
Nanoscale ; 12(5): 3292-3301, 2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-31971195

RESUMO

Surface-enhanced Raman scattering (SERS) and magnetic resonance imaging (MRI)-guided phototherapy are new breakthroughs in cancer therapeutics due to their complementary advantages, such as enhanced imaging spatial resolution and depth. Herein, we synthesized monodispersed Prussian blue-encapsulated gold nanoparticles (Au@PB NPs), in which the plasmonic gold core plus coordination polymer of cyanide (C[triple bond, length as m-dash]N) and iron ions coincidently become a superexcellent contrast agent for both MRI and zero-background SERS imaging. PB, as a signal source for MR and SERS, can be easily assembled onto single Au NPs, of which iron ions possess high relaxation efficiency for in vivo MRI, e.g., the longitudinal and transversal relaxation efficiency values are 0.86 mM-1 s-1 (r1) and 5.42 mM-1 s-1 (r2), respectively. Furthermore, with the help of the plasmonic enhancement of the gold core, the C[triple bond, length as m-dash]N groups exhibit a specific, strong, and stable (3S) SERS emission in the Raman-silent region (1800-2800 cm-1), allowing accurate in vivo imaging at the single or even subcellular level. More importantly, PB has remarkable absorption properties in the near infrared region, and can be used as a photosensitizer for photothermal (PT) and photodynamic (PD) therapy simultaneously. Hence, the ideal integration of a plasmonic Au core and PB shell into a single monodispersed MR-guided NP, with zero-background SERS signals, is an important candidate for both tumor navigation and in situ PT/PD treatment guided by SERS/MR dual-mode imaging.


Assuntos
Meios de Contraste , Ferrocianetos , Ouro , Imageamento por Ressonância Magnética , Nanopartículas , Neoplasias Experimentais , Fármacos Fotossensibilizantes , Fototerapia , Animais , Linhagem Celular Tumoral , Meios de Contraste/química , Meios de Contraste/farmacologia , Ferrocianetos/química , Ferrocianetos/farmacologia , Ouro/química , Humanos , Camundongos , Nanopartículas/química , Nanopartículas/uso terapêutico , Neoplasias Experimentais/diagnóstico por imagem , Neoplasias Experimentais/tratamento farmacológico , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia
19.
Chemosphere ; 247: 125919, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31978660

RESUMO

This study proposes the use of an aluminum-based drinking water treatment residue (DWTR) to adsorb ferrocyanide. The batch tests and chemical characterization results showed that ferrocyanide adsorption increased as the pH, ion strength, and the solid and solution ratio decreased, and as the initial ferrocyanide concentration increased. The pseudo-first (R2 = 0.906) and pseudo-second-order (R2 = 0.966) kinetic models well described the adsorption kinetics, and the adsorption isotherm was also well fittted by Langmuir (R2 = 0.989) and Freundlich (R2 = 0.989) models. The calculated initial ferrocyanide adsorption rate by the pseudo-second-order kinetic model was 0.0190 mg-CN g-1 h-1, and the estimated maximum adsorption capacity determined by the Langmuir model was 20.9 mg-CN g-1. The main structure and elemental distributions showed nearly no change in DWTR after adsorption. Adsorption involved electrostatic interactions and ligand exchanges with Al in DWTR, as evidenced by the 1.40 eV increase in the Al binding energy after adsorption. Furthermore, ferrocyanide adsorption had a dual effect on the DWTR porosity (including both increase and decrease effect), resulting in a slight increase in the specific surface area and total pore volume of DWTR after adsorption. This dual effect was likely related to Fe present in ferrocyanide, which introduced new vacant sites on DWTR. Overall, recycled DWTR is a promising potential adsorbent for ferrocyanide.


Assuntos
Alumínio/química , Ferrocianetos/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Reciclagem
20.
J Colloid Interface Sci ; 565: 483-493, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31982715

RESUMO

The complex biology of glioma compromises therapeutic efficacy and results in poor prognosis. Photodynamic therapy (PDT) has emerged as a promising modality for localized tumor ablation with limited damage to healthy brain tissues. However, low photosensitizer concentration and hypoxic microenvironment in glioma tissue hamper the practical applications of PDT. To address the challenges, biocompatible periodic mesoporous organosilica coated Prussian blue nanoparticles (PB@PMOs) are constructed to load a biosafe prodrug 5-aminolevulinic acid (5-ALA), which is pronouncedly converted to protoporphyrin IX (PpIX) in malignant cells. PB@PMO-5-ALA induces a higher accumulation of PpIX in glioma cells compared to free 5-ALA. Meanwhile, the PB@PMOs, with a mean edge length of 81 nm and good biocompatibility, effectively decompose hydrogen peroxide to oxygen in a temperature-responsive manner. Oxygen supply further contributes to the promotion of 5-ALA-PDT. Thus, the photodynamic effect of PB@PMO-5-ALA is significantly improved, imposing augmented cytotoxicity to glioma U87MG cells. Furthermore, ex vivo fluorescence imaging elucidates the tumor PpIX increases by 75% in PB@PMO-5-ALA treated mice than that in 5-ALA treated ones post 12 h injection. Magnetic resonance imaging (MRI) and iron staining strongly demonstrate the accumulation of PB@PMO-5-ALA in glioma tissues with negative contrast enhancement and blue staining deposits, respectively. The nanoparticle accumulation and high PpIX level collaboratively enhance PDT efficacy through PB@PMO-5-ALA, which efficiently suppresses tumor growth, providing a promising option with safety for local glioma ablation.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Glioma/tratamento farmacológico , Ácidos Levulínicos/farmacologia , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Antineoplásicos/química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Neoplasias Encefálicas/diagnóstico por imagem , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Ensaios de Seleção de Medicamentos Antitumorais , Ferrocianetos/química , Ferrocianetos/farmacologia , Glioma/diagnóstico por imagem , Humanos , Ácidos Levulínicos/química , Nanopartículas/química , Imagem Óptica , Compostos de Organossilício/química , Compostos de Organossilício/farmacologia , Oxigênio/química , Tamanho da Partícula , Fármacos Fotossensibilizantes/química , Porosidade , Pró-Fármacos/química , Pró-Fármacos/farmacologia , Propriedades de Superfície , Microambiente Tumoral/efeitos dos fármacos
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