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1.
J Colloid Interface Sci ; 607(Pt 2): 967-977, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34598033

RESUMO

The inert sites of Prussian Blue Analogue (PBA) seriously affected its electrocatalytic activity and application, how to activate inert sites in PBA to fulfill effective oxygen evolution reduction (OER) is a major challenge. Herein, Mo substituted Fe sites and S doped in inert PBA were designed and synthesized by hydrothermal method to enhance structural stability and OER activity. PBA-SMo/NF shows the optimum activity with a low overpotential of 252 and 294 mV for harvesting current density 20 and 100 mA cm-2, respectively, and exhibits excellent durability under high current density. Theoretical calculation of H2O adsorption energy and Bader charges reveals that Mo sites in PBA-SMo possess favourable H2O adsorption kinetics. More important, Gibbs free energy diagram and DOS show PBA-SMo have lower energy barriers for OER and better conductivity. This work provides a kind of guidance for the design and optimization of PBA for broad applications.


Assuntos
Ferrocianetos , Oxigênio
2.
Food Chem ; 369: 131008, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34500205

RESUMO

In this study, we developed a prussian blue nanoparticles (PBNPs) immunochromatographic assay (ICA) integrated with smartphone-based detection device for ZEN in cereals. PBNPs, as probe labels, were synthesized with properties of controllable structure, environment friendliness, and high affinities to antibody (Ab). PBNPs-ICA quantitative analysis was performed with a hand-held smartphone-based device coupled with a user-friendly and self-programmed detection App. This integrated strategy demonstrated high sensitivity for ZEN with a cut-off value of 10 µg/kg, a detection limit of 0.12 µg/kg, a quantitation limit of 0.27 µg/kg, and recovery rates of 92.0%-105.0% and 88.0%-98.0% for maize and wheat, respectively. The results of 20 naturally contaminated cereal samples showed good correlation (R2>0.99) between LC-MS/MS and developed system. Moreover, the stability experiment revealed that PBNPs-ICA maintained high stability and bioactivity against competitive antigen (Ag). The proposed strategy exhibited great potential for the rapid monitoring of mycotoxins or other small molecule hazards.


Assuntos
Zearalenona , Cromatografia de Afinidade , Cromatografia Líquida , Grão Comestível/química , Ferrocianetos , Contaminação de Alimentos/análise , Limite de Detecção , Smartphone , Espectrometria de Massas em Tandem , Zearalenona/análise
3.
J Hazard Mater ; 423(Pt A): 126972, 2022 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-34461549

RESUMO

Thallium (Tl) often enters the environment via mineral exploitation and utilization. The main restriction of Tl removal is the interference of high concentrations of coexisting ions in wastewater, therefore, enhancing the selectivity for Tl is essential to its treatment. Magnetic Prussian blue particles (Fe3O4@PB), an ion-sieving material with an open structure, were synthesized through a "one-pot" method at room temperature for the highly selective removal of Tl+. The removal percentage of Tl+ was over 92% even when the concentration of coexisting ions (e.g. Zn2+, Cd2+, Cu2+, and Pb2+) were 10,000 times higher than the initial concentration of Tl+. The maximal experimental removal capacity was 528 mg Tl/g Fe3O4@PB, and the removal percentage remained steady at pH 3-10. The high selectivity of Fe3O4@PB for Tl+ is attributed to the fact that hydrated Tl+ has a smaller hydrated diameter and a lower hydration free energy than other coexisting ions, while the rapid adsorption kinetics of Tl+ results from the negative surface charge and the network of nanocapillaries of the Fe3O4@PB. Overall, a new low-cost material that is easy to synthesize and has superior Tl+ removal capacity with extremely high selectivity for Tl+ was obtained for effective magnetic removal of thallium from wastewater.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Adsorção , Ferrocianetos , Fenômenos Magnéticos , Tálio/análise , Poluentes Químicos da Água/análise
4.
Chemosphere ; 290: 133318, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34921861

RESUMO

To fabricate an efficient Cs ion adsorbent and prevent unexpected loss of Prussian blue (PB) colloidal particles during use, PB was immobilized on the surface of electrospun mesoporous silica nanofibers (MSFs) via a newly developed method of double exposure to Fe (III) ions. To introduce PB on MSFs, the MSFs were functionalized with ethylenediamine moiety to bind to Fe (III) ions, which would firmly anchor PB. MSFs were pretreated with Fe (III) ions and exposed to K4 [Fe(II) (CN)6] to form PB. We found that this process did not provide a sufficient PB amount on the MSFs. To increase the PB amount, after initial PB formation, the MSFs were treated with Fe (III) ions again so that the unreacted K4 [Fe(II) (CN)6] remaining on the MSFs could become PB. An investigation of the adsorption isotherms and kinetics of the nanofibrous adsorbent indicated that monolayer chemisorption had occurred. The maximum Cs ion adsorption capacity using the method of double exposure to Fe (III) ions was determined to be 14.66 mg/g, which was higher by a factor of 2.24 than the case that was not prepared by this method. Cs ions were selectively adsorbed over other cations and could be removed in both acidic and basic conditions, presumably because of the robust MSFs.


Assuntos
Nanofibras , Poluentes Químicos da Água , Adsorção , Césio , Ferrocianetos , Íons , Dióxido de Silício
5.
Anal Chim Acta ; 1188: 339188, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34794574

RESUMO

A CoFe Prussian blue analogue (CoFe PB) modified FTO electrode, prepared via a facile electrodeposition method, is investigated as a non-enzymatic glucose sensor under neutral conditions. The electrode exhibits a linear detection of glucose in the 0.1-8.2 mmol/L range with a detection limit of 67 µM, a sensitivity of 18.69 µA/mM.cm2, and a fast response time of less than 7 s under neutral conditions. Its stability is confirmed with both electrochemical experiments and characterization studies performed on the pristine and post-mortem electrode. We also conducted a comprehensive electrochemical analysis to elucidate the identity of the active site and the glucose oxidation mechanism on the Prussian blue surface.


Assuntos
Técnicas Eletroquímicas , Glucose , Cobalto , Eletrodos , Ferrocianetos
6.
Chem Commun (Camb) ; 57(77): 9870-9873, 2021 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-34490866

RESUMO

Herein, we develop a novel 3D composite aerogel (3D PB/GMA) and apply it to the real-time monitoring of H2O2 secretion from living cells. The 3D PB/GMA shows an obvious porous structure and superior peroxidase-like activity. The electrochemical sensor based on 3D PB/GMA shows an excellent electrocatalytic performance towards H2O2. When applied to the real-time tracking of H2O2 secretion from living cells, it can satisfactorily distinguish cancer cell lines from normal cell lines, revealing a good application potential in pathological diagnosis.


Assuntos
Ferrocianetos/química , Grafite/química , Peróxido de Hidrogênio/análise , Linhagem Celular Tumoral , Géis/química , Humanos , Fatores de Tempo
7.
Int J Nanomedicine ; 16: 6003-6016, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34511902

RESUMO

Introduction: Traditional antitumor chemotherapy faces great challenges, such as multi-drug resistance (MDR) and poor penetration into tumor tissues. The newly emerging nitric oxide (NO)-based gas therapy has been recognized to reduce MDR and has improved permeation into tumor tissue. Methods: In this study, NO-generating prodrug sodium nitroprusside (SNP) was doped to hollow mesoporous Prussian blue (PB) nanoparticles to fabricate NO-generating nanoparticles (NO-PB), which was further loaded with doxorubicin (DOX). Results: DOX loaded NO-PB (DOX-NO-PB) was released quicker at pH 6 compared with neutral pH, suggesting NO-PB may facilitate the release of loaded drug in acidic tumor tissue. The capacity of NO production by NO-PB was measured, and the results showed the presence of NO in the culture medium from 4T1 cells incubated with NO-PB and inside the cells. NP-PB could be detected by photoacoustic imaging (PAI) in tumor tissue in 4T1 tumor bearing mice, suggesting this nanoparticle may serve as contrast agent for the noninvasive diagnosis of tumor tissues. NO-PB suppressed the growth of tissues in 4T1 tumor bearing mice. DOX-NO-PB showed more potent anti-tumor effects in 4T1 cells and tumor bearing mice compared with free DOX and NO-PB alone, indicating that the combination of DOX and NO-PB exhibited synergistic effects on tumor suppression. Conclusion: This study provides a novel nanocarrier for gas therapy with additional PAI imaging capacity. This nanocarrier can be utilized for combination therapy of NO and chemotherapeutics which may serve as theranostic agents.


Assuntos
Nanopartículas , Neoplasias , Técnicas Fotoacústicas , Animais , Doxorrubicina/farmacologia , Ferrocianetos , Camundongos , Óxido Nítrico
8.
Astrobiology ; 21(9): 1121-1136, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34534004

RESUMO

Considered one of the most promising building blocks of life on primitive Earth, cyanide and its complexes are likely to have played an important role in the emergence of life on the planet. Investigation into cyanide on Earth has primarily considered high concentrations, but the cyanide concentration in the oceans of prebiotic Earth was exceptionally low. Thus, Bernal's hypothesis has allowed investigators to work around this problem. We observed, however, that cyanide does not adsorb onto several minerals; therefore, ferrocyanide could be used as a cyanide source when adsorbed onto mineral surfaces to promote the synthesis of molecules of biological significance. When adsorbed onto bentonite, a mineral that has Fe3+ atoms in its interlayers, the formation of Prussian blue analog complexes occurs through endothermic reaction and with increased entropy. The adsorption of ferrocyanide onto kaolinite indicates an exothermic and outer-sphere interaction, which results in degeneracy breakdown for C ≡ N stretch energy into two new bands of FTIR-ATR spectrum. Magnetite, which has iron atoms in its structure, and ferrocyanide interactions have been observed by outer-sphere coordination as well as the formation of Prussian blue analogs, as confirmed by the appearance of a new doublet in the Mössbauer spectra and a broadband close to 750 nm at UV-visible spectroscopy. Magnetite and kaolinite experiments presented relevant results only when performed in seawater, which suggests the importance of seawater composition for prebiotic experiments. These obtained results prove that ferrocyanide interacts with minerals differently according to structure and composition and show that this complex, like the Prussian blue analogs, may have played a crucial role as a source of cyanide on primitive Earth.


Assuntos
Ferrocianetos , Prebióticos , Adsorção , Planeta Terra , Minerais
9.
Biosens Bioelectron ; 193: 113627, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34534889

RESUMO

Over the past decades, due to the desire for artificial umami flavors, apparatuses for detecting the umami taste have constantly been developed. Nevertheless, most information on umami is still acquired through human sensory assessment, which makes it difficult to establish an umami standard or quantify the umami flavor. In this study, the ligand binding domain called venus flytrap (VFT) domain of the umami taste receptor protein T1R1 was used as a recognition element, and an electrochemical biosensor based on a double-signal amplification strategy was constructed using single-walled carbon nanotubes (SWCNTs) and Prussian blue (PB). Moreover, the umami taste of four representative umami substances, inosine-5'-monophosphate (IMP), monosodium L-glutamate (MSG), beefy meaty peptide (BMP), and sodium succinate (WSA), were successfully quantitatively measured using differential pulse voltammetry (DPV) at an electrochemical workstation. Based on an equation (S/N = 3), the low detection limits (LODs) of IMP, MSG, BMP, and WSA were 0.1, 0.1, 0.1, and 0.01 pM, respectively. Meanwhile, a normalized signal intensity of more than 90% was kept for 4 days. The results showed that the biosensor could be used to detect umami substances with high sensitivity and selectivity, and was shown to have human-like performance. To develop the T1R1-VFT biosensor using the above-mentioned method, we utilized the ligand binding domain of the human umami receptor, rather than the entire umami receptor protein, which had a complex structure, having the following advantages: volume reduction, simplicity, and stability. This method has great potential for the detection of umami tastes, instead of using sensory evaluation, and for the development of new artificial flavorings.


Assuntos
Técnicas Biossensoriais , Droseraceae , Nanotubos de Carbono , Galvanoplastia , Ferrocianetos , Humanos , Ligantes , Receptores Acoplados a Proteínas G/genética
10.
Nanoscale ; 13(38): 16104-16112, 2021 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-34486632

RESUMO

Ultraviolet A (UVA) irradiation can induce cellular senescence and cause skin photoaging, which is mainly driven by the excessive production of reactive oxygen species (ROS). Emerging studies have focused on new strategies for the prevention of skin photoaging. Ultrasmall Prussian blue nanoparticles (USPBNPs) demonstrate an intensive ability to scavenge ROS as nanozymes and exhibit great potential in the treatment of ROS-related diseases. Our goal was to investigate the anti-senescent role of USPBNPs against UVA-induced premature senescence in human dermal fibroblasts (HDFs). Our results showed that the activation of senescence-associated ß-galactosidase (SA-ß-gal) and the arrest of the cell cycle induced by UVA radiation in HDFs were significantly inhibited by pretreatment of USPBNPs (1 µg ml-1). Furthermore, USPBNPs downregulated the expression of DNA damage marker γH2AX and inhibited the secretion of senescence-associated secretory phenotypes (SASP) including IL-6, TNF-α and matrix metalloproteinases (MMPs). In addition, we found that the antiphotoaging effect of USPBNPs involved the scavenging of ROS as well as the inhibition of the ERK/AP-1 pathway. In conclusion, USPBNPs exhibited great potential to become novel anti-photoaging agents by alleviating UVA-induced cellular senescence and thus delaying the process of skin photoaging.


Assuntos
Nanopartículas , Fator de Transcrição AP-1 , Células Cultivadas , Senescência Celular , Ferrocianetos , Fibroblastos , Humanos , Espécies Reativas de Oxigênio , Pele , Raios Ultravioleta
11.
Analyst ; 146(17): 5236-5244, 2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34378551

RESUMO

Detection of specific DNA is important in many fields. Label-free DNA sensing performed by electrochemical impedance spectroscopy (EIS) or using a quartz crystal microbalance (QCM) is widely employed for this purpose. Gold electrodes are mainly used for these techniques due to their chemical stability. However, ferro/ferricyanide used as a redox couple was found to etch the gold electrode and this significantly limited the repeatability of the EIS measurement. Inductively coupled plasma mass spectrometry (ICP-MS) and QCM experiments provided important clues about the gold dissolution mechanism and revealed that phosphate buffer promotes the dissolution of gold in the presence of the ferri/ferrocyanide redox couple. Tris buffered conditions, which provide the most stable environment, enabled the investigation of experimental parameters with a Q-sense electrochemistry module (QEM), which can perform QCM and EIS measurements simultaneously and revealed the principal factors that influence changes in the impedance. With the reproducible measurements, the estimation of an optimum probe-DNA concentration for detecting complementary DNA is demonstrated. In order to amplify the detection signal of target DNA, we sought to maximize the difference in response between the probe-only and target DNA by controlling the concentration of probe DNA. We showed that an intermediate probe-DNA concentration yields optimum signal amplification.


Assuntos
Técnicas Biossensoriais , Ouro , Eletrodos , Ferrocianetos , Oxirredução
12.
Colloids Surf B Biointerfaces ; 207: 112018, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34391167

RESUMO

Complete treatment of cancer remains a major challenge today. Herein, a biocompatible drug delivery system named as PCM + PTX@mPBs/PEG was constructed. In this system, Paclitaxel (PTX) was blended with phase-change material (PCM) and loaded in mesoporous Prussian blue nanoparticles (mPBs), and chelated with polyethylene glycol at surface. The blank PCM@mPBs/PEG had uniform particle size distribution, large pore size to load drug, excellent photothermal efficiency and good biocompatibility. After loading PTX, PCM + PTX@mPBs/PEG was demonstrated with a high loading capacity and the drug presented temperature-responsive release characteristics. In addition, PTX can be released under the exposure of an NIR laser. In vitro cell experiments showed that nanoparticles can be exposed to near-infrared irradiation to increase uptake in cells, which enhanced anticancer activity. After tail vein injection of PCM + PTX@mPBs/PEG suspension in tumor-bearing mice, PCM + PTX@mPBs/PEG can accumulate at the tumor site through passive transport. The tumor was effectively suppressed by phototherapy and chemotherapy with few side effects. In summary, compared with photothermal therapy or chemotherapy alone, the prepared PCM + PTX@mPBs/PEG showed synergistic photothermal and chemotherapeutic effects on cancer treatment of mice.


Assuntos
Nanopartículas , Neoplasias , Animais , Linhagem Celular Tumoral , Sistemas de Liberação de Medicamentos , Ferrocianetos , Camundongos , Neoplasias/tratamento farmacológico , Paclitaxel/farmacologia , Fototerapia , Terapia Fototérmica
13.
Biosensors (Basel) ; 11(8)2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34436083

RESUMO

Due to the great threat posed by excessive nitrite in food and drinking water to human health, it calls for developing reliable, convenient, and low-cost methods for nitrite detection. Herein, we string nanozyme catalysis and diazotization together and develop a ratiometric colorimetric approach for sensing nitrite in food. First, hollow MnFeO (a mixture of Mn and Fe oxides with different oxidation states) derived from a Mn-Fe Prussian blue analogue is explored as an oxidase mimic with high efficiency in catalyzing the colorless 3,3',5,5'-tetramethylbenzidine (TMB) oxidation to blue TMBox, presenting a notable signal at 652 nm. Then, nitrite is able to trigger the diazotization of the product TMBox, not only decreasing the signal at 652 nm but also producing a new signal at 445 nm. Thus, the analyte-induced reverse changes of the two signals enable us to establish a ratiometric colorimetric assay for nitrite analysis. According to the above strategy, facile determination of nitrite in the range of 3.3-133.3 µM with good specificity was realized, providing a detection limit down to 0.2 µM. Compared with conventional single-signal analysis, our dual-signal ratiometric colorimetric mode was demonstrated to offer higher sensitivity, a lower detection limit, and better anti-interference ability against external detection environments. Practical applications of the approach in examining nitrite in food matrices were also verified.


Assuntos
Colorimetria , Nitritos , Benzidinas , Catálise , Água Potável , Ferrocianetos , Humanos , Limite de Detecção , Nanoestruturas , Oxirredução
14.
Water Res ; 203: 117551, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34418645

RESUMO

A new water treatment technology is presented for extending the longevity and increasing the maximal bio-load of container-bound, lucrative live seafood transportations. The technology is designed for removing ammonia and minimizing the bacterial concentration that develop in the water during the transport. This paper focuses on the characteristics of self-synthesized polyether-sulfone (PES) coated Zn-HCF composite beads, which have a high adsorbing capacity for NH4+ in seawater and constitute the heart of the developed technology. Adsorption isotherms show that the operational capacity of the composite material (PES = 20% w/w) at NH4+ concentration of 10 mgN/L at 3.5 °C is ∼3 mgN/g Zn-HCF. The kinetics of the PES-coated beads were shown to be considerably slower than the bare Zn-HCF, but since the retention time in the transport is long (many days), this does not detract from the effectiveness of the adsorption. Simulation experiments with and without live fish showed that the adsorbing material behaved as expected during a 21-d trip and that it did not have any effect on the fish. Repeated adsorption/regeneration (3 and 6 M NaCl) tests proved the composite material's stability and ion-exchange robustness. Electrooxidation of the ammonia in the exhausted regeneration solution was carried out with high efficiency and the treated solution could be used effectively in the following chemical regeneration step. The cost of a treatment unit installed in a 40-foot container was estimated at $40,000 and the ROI at 6 to 12 months.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Adsorção , Amônia , Ferrocianetos , Concentração de Íons de Hidrogênio , Cinética , Alimentos Marinhos , Temperatura , Poluentes Químicos da Água/análise , Zinco
15.
Nan Fang Yi Ke Da Xue Xue Bao ; 41(6): 909-915, 2021 Jun 20.
Artigo em Chinês | MEDLINE | ID: mdl-34238744

RESUMO

OBJECTIVE: To prepare Mn2+-doped Prussian blue nanoparticles (Mn-PB NPs) for T1-T2 dual-mode magnetic resonance imaging (MRI) and photothermal therapy in vitro. OBJECTIVE: Mn-PB NPs were prepared based on manganese chloride, ferrous chloride and potassium ferricyanide using the microemulsion method. The performance of T1-T2 dual-mode MRI with Mn-PB NPs and the photothermal property of the nanoparticles were assessed. CCK-8 assay and AM/PI double staining were used to evaluate the effect of photothermal therapy in vitro using the parepared nanoparticles. OBJECTIVE: The prepared Mn-PB NPs had a mean particle size of 39.46±0.42 nm with a Zeta potential of -25.9±1.2 mV and exhibited a good dispersibility and uniform particle size. In MRI using the nanoparticles, the r1 and r2 values reached 0.68 and 3.65 (mmol/L)-1s-1, respectively, indicating good performance of Mn-PB NPs for T1 and T2 enhancement in MRI. When irradiated with 808 nm laser for 10 min, Mn-PB NPs showed a temperature rise to 90 ℃ to cause significant reduction of cell survival. CCK-8 assay and AM/PI double staining confirmed that Mn-PB NPs were capable of efficient killing of HepG2 cells upon 808 nm laser irradiation. OBJECTIVE: The Mn-PB NPs prepared in this work have uniform particle size and show good performances both in MRI for T1 and T2 enhancement and in photothermal therapy in vitro without obvious cytotoxicity.


Assuntos
Nanopartículas , Terapia Fototérmica , Linhagem Celular Tumoral , Ferrocianetos , Imageamento por Ressonância Magnética
16.
J Colloid Interface Sci ; 603: 856-863, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34242989

RESUMO

Heterogeneous activation of peroxymonosulfate (PMS) is one of the most promising techniques for wastewater treatment. Herein, an ingenious system by coupling of photocatalysis and PMS activation was developed, using hollow-structured amorphous prussian blue (A-PB) decorated on graphitic carbon nitride (g-C3N4) as the catalyst. Degradation of bisphenol A (BPA) via the A-PB-g-C3N4 mediated PMS activation under visible light (Vis) was systematically investigated. Astonishingly, it was found that ~ 82.0%, 92.6%, 98.2% and 99.3% of BPA (40 mg/L) were removed within 2, 4, 6 and 7 min, respectively, suggesting the extremely strong oxidizing capacity of the A-PB-g-C3N4/PMS/Vis system. Synergistic effect between the decorated A-PB and the g-C3N4 substrate promoted the Fe(III)/Fe(II) redox cycling and facilitated the charge transfer at the A-PB/g-C3N4 heterojunction interface. As a result, both photocatalysis and heterogeneous activation of PMS were boosted in the A-PB-g-C3N4/PMS/Vis system, leading to the production of large amount of reactive oxygen species (ROS). The various ROS (SO4•-, HO•, •O2- and 1O2) was responsible for the ultrafast degradation of BPA. Moreover, the A-PB-g-C3N4 catalyst also exhibited outstanding reusability and stability, retaining 98.9% of the removal percentage for BPA after five consecutive reaction cycles. This study suggests that the A-PB-g-C3N4 can be an all-rounder to bridge photocatalysis and PMS activation, and shed a new light on the application of multiple ROS for the ultrafast elimination of micropollutants from wastewater.


Assuntos
Compostos Férricos , Peróxidos , Ferrocianetos , Grafite , Compostos de Nitrogênio
17.
Anal Chim Acta ; 1175: 338749, 2021 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-34330447

RESUMO

A new disposable amperometric biosensor for sarcosine (Sar, a biomarker for prostate cancer) was designed based on screen-printed carbon electrodes, Prussian blue, polymer dispersed reduced graphene oxide (P-rGO) nanosheets, and sarcosine oxidase (SOx). Poly(sodium 4-styrenesulfonate-r-LAHEMA) denoted as PSSL was newly synthesized as dispersant for rGO. The P-rGO was utilized for SOx immobilization, the sulfonate and disulfide functionalities in PSSL enable physical adsorption of SOx and its bioactivity and stability properties were improved. The biosensor was optimized by various enzyme concentration, applied potential, and operating pH. Under the optimized conditions, the biosensor exhibited maximum current responses within 5 s at an applied potential of -0.1 V vs. integrated Ag/AgCl reference electrode. The biosensor had a dynamic linear range of 10-400 µM, with a sensitivity of 9.04 µA mM-1 cm-2 and a low detection limit of 0.66 µM (S/N = 3). Additionally, the biosensor possesses strong anti-interference capability, high reproducibility, and storage stability over 3 weeks. Furthermore, its clinical applicability was tested in urine samples from both prostate cancer patients and healthy control, and the analytical recoveries were satisfactory. Therefore, this biosensor has significant potential in the rapid and non-invasive point-of-care testing for prostate cancer diagnosis.


Assuntos
Técnicas Biossensoriais , Sarcosina , Eletrodos , Enzimas Imobilizadas , Ferrocianetos , Grafite , Humanos , Limite de Detecção , Masculino , Polímeros , Reprodutibilidade dos Testes
18.
J Synchrotron Radiat ; 28(Pt 4): 1127-1136, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34212876

RESUMO

In order to disentangle the physical effects at the origin of transition metal K-edge X-ray magnetic circular dichroism (XMCD) in coordination polymers and quantify small structural distortions from the intensity of these signals, a systematic investigation of Prussian blue analogs as model compounds is being conducted. Here the effects of the temperature and of the external magnetic field are tackled; none of these external parameters modify the shape of the XMCD signal but they both critically modify its intensity. The optimized experimental conditions, as well as a reliable and robust normalization procedure, could thus be determined for the study of the intrinsic parameters. Through an extended discussion on measurements on other XMCD-dedicated beamlines and for other coordination compounds, we finally provide new transition metal K-edge XMCD users with useful information to initiate and successfully carry out their projects.


Assuntos
Dicroísmo Circular/métodos , Ferrocianetos/química , Polímeros/química , Campos Magnéticos , Temperatura , Raios X
19.
Biosensors (Basel) ; 11(6)2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34200755

RESUMO

Prussian blue analogs (PBAs) are well-known artificial enzymes with peroxidase (PO)-like activity. PBAs have a high potential for applications in scientific investigations, industry, ecology and medicine. Being stable and both catalytically and electrochemically active, PBAs are promising in the construction of biosensors and biofuel cells. The "green" synthesis of PO-like PBAs using oxido-reductase flavocytochrome b2 is described in this study. When immobilized on graphite electrodes (GEs), the obtained green-synthesized PBAs or hexacyanoferrates (gHCFs) of transition and noble metals produced amperometric signals in response to H2O2. HCFs of copper, iron, palladium and other metals were synthesized and characterized by structure, size, catalytic properties and electro-mediator activities. The gCuHCF, as the most effective PO mimetic with a flower-like micro/nano superstructure, was used as an H2O2-sensitive platform for the development of a glucose oxidase (GO)-based biosensor. The GO/gCuHCF/GE biosensor exhibited high sensitivity (710 A M-1m-2), a broad linear range and good selectivity when tested on real samples of fruit juices. We propose that the gCuHCF and other gHCFs synthesized via enzymes may be used as artificial POs in amperometric oxidase-based (bio)sensors.


Assuntos
Técnicas Biossensoriais , Ferrocianetos/química , Peroxidase/análise , Fontes de Energia Bioelétrica , Eletroquímica , Eletrodos , Enzimas Imobilizadas , Glucose , Glucose Oxidase , Grafite , Peróxido de Hidrogênio , Oxirredutases , Paládio , Peroxidases
20.
Int J Mol Sci ; 22(11)2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34206067

RESUMO

Nanozymes, nanomaterials with enzyme-like activities, are becoming powerful competitors and potential substitutes for natural enzymes because of their excellent performance. Nanozymes offer better structural stability over their respective natural enzymes. In consequence, nanozymes exhibit promising applications in different fields such as the biomedical sector (in vivo diagnostics/and therapeutics) and the environmental sector (detection and remediation of inorganic and organic pollutants). Prussian blue nanoparticles and their analogues are metal-organic frameworks (MOF) composed of alternating ferric and ferrous irons coordinated with cyanides. Such nanoparticles benefit from excellent biocompatibility and biosafety. Besides other important properties, such as a highly porous structure, Prussian blue nanoparticles show catalytic activities due to the iron atom that acts as metal sites for the catalysis. The different states of oxidation are responsible for the multicatalytic activities of such nanoparticles, namely peroxidase-like, catalase-like, and superoxide dismutase-like activities. Depending on the catalytic performance, these nanoparticles can generate or scavenge reactive oxygen species (ROS).


Assuntos
Ferrocianetos/química , Estruturas Metalorgânicas/química , Nanopartículas/química , Nanoestruturas/química , Catalase , Catálise , Complexos de Coordenação/química , Ferro/química , Oxirredução , Peroxidase , Espécies Reativas de Oxigênio
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