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1.
Biosens Bioelectron ; 262: 116547, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38968775

RESUMO

5-formylcytosine (5 fC) and 5-carboxylcytosine (5caC) serve as key intermediates in DNA demethylation process with significant implications for gene regulation and disease progression. In this study, we introduce a novel electrochemical sensing platform specifically designed for the sensitive and selective detection of 5 fC and 5caC in DNA. Protein A-modified magnetic beads (ProtA-MBs) coupled with specific antibodies facilitate the immunorecognition and enrichment of these modified bases. Signal amplification is achieved through several chemical reactions involving the interaction between N3-kethonaxl and guanine, copper-free click chemistry for the attachment of dibenzocyclooctyne (DBCO)-Biotin, and the subsequent recognition by streptavidin-conjugated horseradish peroxidase (SA-HRP). The assay's readout is performed on a disposable laser-induced graphene (LIG) electrode, modified with the bead-antibody-DNA complex in a magnetic field, and analyzed using differential pulse voltammetry in a system employing hydroquinone (HQ) as the redox mediator and H2O2 as the substrate. This immunosensor displayed excellent sensitivity, with detection limits of 14.8 fM for 5 fC across a 0.1-1000 pM linear range and 87.4 fM for 5caC across a 0.5-5000 pM linear range, and maintained high selectivity even in the presence of interferences from other DNA modifications. Successful application in quantifying 5 fC and 5caC in genomic DNA from cell extracts, with recovery rates between 97.7% to 102.9%, underscores its potential for clinical diagnostics. N3-kethoxal was used for the first time in an electrochemical sensor. This work not only broadens the toolkit for detecting DNA modifications but also provides a fresh impetus for the development of point-of-care testing (POCT) technologies.

2.
J Environ Sci (China) ; 146: 118-126, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38969440

RESUMO

With the increasing demand of recycling disposal of industrial wastewater, oil-in-water (O/W) emulsion has been paid much attention in recent years owing to its high oil content. However, due to the presence of surfactant and salt, the emulsion was usually stable with complex physicochemical interfacial properties leading to increased processing difficulty. Herein, a novel flow-through electrode-based demulsification reactor (FEDR) was well designed for the treatment of saline O/W emulsion. In contrast to 53.7% for electrical demulsification only and 80.3% for filtration only, the COD removal efficiency increased to 92.8% under FEDR system. Moreover, the pore size of electrode and the applied voltage were two key factors that governed the FEDR demulsification performance. By observing the morphology of oil droplets deposited layer after different operation conditions and the behavior of oil droplets at the electrode surface under different voltage conditions, the mechanism was proposed that the oil droplets first accumulated on the surface of flow-through electrode by sieving effect, subsequently the gathered oil droplets could further coalesce with the promoting effect of the anode, leading to a high-performing demulsification. This study offers an attractive option of using flow-through electrode to accomplish the oil recovery with simultaneous water purification.


Assuntos
Eletrodos , Filtração , Eliminação de Resíduos Líquidos , Purificação da Água , Purificação da Água/métodos , Filtração/métodos , Eliminação de Resíduos Líquidos/métodos , Óleos/química , Águas Residuárias/química , Poluentes Químicos da Água/química , Emulsões/química , Técnicas Eletroquímicas/métodos , Técnicas Eletroquímicas/instrumentação
3.
J Electr Bioimpedance ; 15(1): 85-88, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38962505

RESUMO

There are various methods for cell growth monitoring. However, most of these methods have drawbacks, such as being invasive, not providing real-time results, or being costly. In this study, we present an alternate method of cell growth monitoring, which is low-cost, non-invasive, real-time, and uses Electrical Impedance Spectro-scopy (EIS). In this work, commercially available culture plates were fitted with custom tetrapolar electrodes, and mouse cells were cultured on them. The variation of culture media impedance, resulting from cell growth, proliferation and other metabolic activities, was recorded over a period of seven days. The results demonstrated an initial increase in impedance corresponding with the cell growth phase, followed by a decrease during the cell death (apoptosis) phase, as confirmed by microscope images. Overall, the results show that our method to monitor cell growth using tetrapolar electrodes is promising and can be further refined for related applications.

4.
Artigo em Inglês | MEDLINE | ID: mdl-38965043

RESUMO

Solid oxide electrolysis cells (SOECs) show significant promise in converting CO2 to valuable fuels and chemicals, yet exploiting efficient electrode materials poses a great challenge. Perovskite oxides, known for their stability as SOEC electrodes, require improvements in electrocatalytic activity and conductivity. Herein, vanadium(V) cation is newly introduced into the B-site of Sr2Fe1.5Mo0.5O6-δ perovskite to promote its electrochemical performance. The substitution of variable valence V5+ for Mo6+ along with the creation of oxygen vacancies contribute to improved electronic conductivity and enhanced electrocatalytic activity for CO2 reduction. Notably, the Sr2Fe1.5Mo0.4V0.1O6-δ based symmetrical SOEC achieves a current density of 1.56 A cm-2 at 1.5 V and 800 °C, maintaining outstanding durability over 300 h. Theoretical analysis unveils that V-doping facilitates the formation of oxygen vacancies, resulting in high intrinsic electrocatalytic activity for CO2 reduction. These findings present a viable and facile strategy for advancing electrocatalysts in CO2 conversion technologies.

5.
Food Chem ; 458: 140296, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38959806

RESUMO

An effective electrochemical sensor was developed to detect and determine of the As(III) by modifying the carbon paste electrode (CPE) with graphitic carbon nitride decorated with iron-based metal-organic frameworks (Fe-MOF/g-C3N5). The differential pulse anodic stripping voltammetry (DPASV) method was used to analyze As(III) ions in a phosphate buffer solution (0.10 M, pH = 5). Fe-MOF/g-C3N5/CPE showed high sensitivity (4.24 µA µg-1 L), satisfactory linear range (0.50 µg L-1-5.00 µg L-1 and 5.00 µg L-1-30.00 µg L-1), and low detection limit (LOD, 0.013 µg L-1). The prepared sensor was showed an excellent repeatability and selectivity, and successfully used for determination of the As(III) ion in ambient waters and apple juice samples.

6.
Electrophoresis ; 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38962855

RESUMO

Miniaturized systems have attracted much attention with the recent advances in microfluidics and nanofluidics. From the capillary electrophoresis, the development of glass-based microfluidic and nanofluidic technologies has supported advances in microfluidics and nanofluidics. Most microfluidic systems, especially nanofluidic systems, are still simple, such as systems constructed with simple straight nanochannels and bulk-scale electrodes. One of the bottlenecks to the development of more complicated and sophisticated systems is to develop the locally integrated nano-electrodes. However, there are still issues with integrating nano-electrodes into nanofluidic devices because it is difficult to fit the nano-electrode size into a nanofluidic channel at the nanometer level. In this study, we propose a new method for the fabrication of local nano-electrodes in nanofluidic devices with nanofluidic and nano-electrochemistry-based experiments. An electroplating solution was introduced to a nanochannel with control of the flow and the electroplating reaction, by which nano-electrodes were successfully fabricated. In addition, a nanofluidic device was available for nanofluidic experiments with the application of 200 kPa. This method can be applied to any electroplating material such as gold and copper. The local nano-electrode will make a significant contribution to the development of more complicated and sophisticated nanofluidic electrophoresis systems and to local electric detection methods for various nanofluidic devices.

7.
Front Plant Sci ; 15: 1367781, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38952844

RESUMO

The large water demand, insufficient deposition on the back of the leaf and the uneven distribution of droplets are the problems of traditional agricultural ground plant protection machinery, which leads to low agricultural control efficiency. Combined with the advantages of electrostatic spray technology and the characteristics of high working efficiency and low probability of droplets drift of ground sprayer, an inductive electrostatic boom spray system based on embedded electrode structure is designed and mounted on a large self-propelled boom sprayer for field testing. Based on the working characteristics of the fan nozzle and the analysis of the theory of charge, the inductive electrostatic spray device is designed. The performance of the device is tested and the rationality of the system design is verified by COMSOL numerical simulations, charge-to-mass ratio, and particle size distribution measurements. The spray deposition scanning software and the Box-Behnken experimental design method are used to analyze the spray droplet deposition rate and coverage density of the sprayer on the front and back of the target leaves. The results show that the embedded closed electrode structure designed in this paper can avoid the problem of electrode wetting, and the electric field generated by it is mainly concentrated in the spray liquid film area, and the intensity reaches 6~7 V/m. At the conventional application height (500 mm), the maximum charge-to-mass ratio is 2.91 mC/kg, and the average particle size is 168.22 µm, which is 12.87% lower than that of ordinary spray, when the spray pressure is 0.3 MPa and the electrostatic voltage is 12 kV. The results of field experiments show that the optimum combination of the working parameters with the spray speed is 8.40 m/s, the spray pressure is 0.35 MPa, the charging voltage is 11.50 kV, the amount of droplet deposition in the lower dorsal area of the blade is 1.44 µL·cm-2. This study can provide a certain basis for the application of electrostatic spray technology in ground sprayers.

8.
ChemSusChem ; : e202400582, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38953395

RESUMO

In the chemical industry, formaldehyde is an important bulk chemical. The traditional synthesis of formaldehyde involves an energy intensive oxidation of methanol over a metal oxide catalyst. The selective electrochemical oxidation of methanol is challenging. Herein, we report a catalytic system with an immobilized TEMPO electrode that selectively oxidizes methanol to formaldehyde with high turnover numbers. Upon the addition of various organic and inorganic bases, the activity of the catalyst could be tuned. The highest Faradaic efficiency that was achieved was 97.5 %, the highest turnover number was 17100. Additionally, we found that the rate determining step changed from the step in which the carbonyl specie is created from the methanol-TEMPO adduct to the oxidative regeneration of the TEMPO+ species. Finally, we showed that the system could be applied to the oxidation of other aliphatic alcohols.

9.
ACS Sens ; 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38954790

RESUMO

Brain organoids are being recognized as valuable tools for drug evaluation in neurodegenerative diseases due to their similarity to the human brain's structure and function. However, a critical challenge is the lack of selective and sensitive electrochemical sensing platforms to detect the response of brain organoids, particularly changes in the neurotransmitter concentration upon drug treatment. This study introduces a 3D concave electrode patterned with a mesoporous Au nanodot for the detection of electrochemical signals of dopamine in response to drugs in brain organoids for the first time. The mesoporous Au nanodot-patterned film was fabricated using laser interference lithography and electrochemical deposition. Then, the film was attached to a polymer-based 3D concave mold to obtain a 3D concave electrode. Midbrain organoids generated from Parkinson's disease (PD) patient-derived iPSCs with gene mutations (named as PD midbrain organoid) or normal midbrain organoids were positioned on the developed 3D concave electrode. The 3D concave electrode showed a 1.4 times higher electrochemical signal of dopamine compared to the bare gold electrode. And the dopamine secreted from normal midbrain organoids or PD midbrain organoids on the 3D concave electrode could be detected electrochemically. After the treatment of PD midbrain organoids with levodopa, the drug for PD, the increase in dopamine level was detected due to the activation of dopaminergic neurons by the drug. The results suggest the potential of the proposed 3D concave electrode combined with brain organoids as a useful tool for assessing drug efficacy. This sensing system can be applied to a variety of organoids for a comprehensive drug evaluation.

10.
Angew Chem Int Ed Engl ; : e202410734, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38958047

RESUMO

Since the discovery in 2000, conversion-type materials have emerged as a promising negative-electrode candidate for next-generation batteries with high capacity and tunable voltage, limited by low reversibility and severe voltage hysteresis. Heterogeneous construction stands out as a cost-effective and efficient approach to reducing reaction barriers and enhancing energy density. However, the second term introduced by conventional heterostructure inevitably complicates the electrochemical analysis and poses great challenges to harvesting systematic insights and theoretical guidance. A model cell is designed and established herein for the conversion reactions between Na and TMSA-SnO2, where TMSA-SnO2 represents single atom modification of eight different 3d transition elements (V, Cr, Mn, Fe, Co, Ni, Cu or Zn). Such a model unit fundamentally eliminates the interference from the second phase and thus enables independent exploration of activation manifestations of the heterogeneous architecture. For the first time, a thermodynamically dependent catalytic effect is proposed and verified through statistical data analysis. The mechanism behind the unveiled catalytic effect is further elucidated by which the active d orbitals of transition metals weaken the surface covalent bonds and lower the reaction barriers. This research provides both theoretical insights and practical demonstrations of the advanced heterogeneous electrodes.

11.
Cochlear Implants Int ; : 1-8, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38958389

RESUMO

OBJECTIVES: Proper electrode placement is essential for favorable hearing outcomes following cochlear implantation. Though often used, traditional intraoperative X-ray imaging is time consuming, exposes patients and staff to radiation, and poses interpretational challenges. The Nucleus® SmartNav System, utilizes electrode voltage telemetry (EVT) to analyze the positioning of the electrode array intraoperatively. This study investigates the efficacy of SmartNav in optimizing the efficiency and accuracy of assessing electrode placement. METHODS: This prospective clinical study analyzed placement of 50 consecutive Cochlear Corporation cochlear implants conducted at a single institution between March of 2022 and June of 2023. Placement check of electrode array using SmartNav and X-ray was completed and individually assessed. A comparative analysis of SmartNav and X-ray completion times for electrode placement assessment was conducted. RESULTS: Subjects included nine ears with abnormal anatomy and three reimplants. SmartNav placement check required a total time of 2.12 min compared to X-ray imaging at 14.23 min (p = 1.6E-16, CI 95%). Both SmartNav and X-ray had excellent sensitivity of 100% in identifying appropriate electrode position (p = 1.0). Tip fold-over was identified using both modalities in 3 cases with noted easier interpretation using SmartNav. CONCLUSION: The Nucleus® SmartNav System significantly outperformed traditional X-ray imaging, offering a faster and more straightforward approach to assessing electrode positioning during cochlear implant surgery, thereby enhancing surgical efficiency and patient safety.

12.
Mikrochim Acta ; 191(8): 443, 2024 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-38955844

RESUMO

CoFe@C was first prepared by calcining the precursor of CoFe-metal-organic framework-74 (CoFe-MOF-74), then an electrochemical sensor for the determination of neohesperidin dihydrochalcone (NHDC) was constructed, which was stemmed from the novel CoFe@C/Nafion composite film modified glassy carbon electrode (GCE). The CoFe@C/Nafion composite was verified by field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). Electrochemical impedance spectroscopy (EIS) was used to evaluate its electrical properties as a modified material for an electrochemical sensor. Compared with CoFe-MOF-74 precursor modified electrode, CoFe@C/Nafion electrode exhibited a great synergic catalytic effect and extremely increased the oxidation peak signal of NHDC. The effects of various experimental conditions on the oxidation of NHDC were investigated and the calibration plot was tested. The results bespoken that CoFe@C/Nafion GCE has good reproducibility and anti-interference under the optimal experimental conditions. In addition, the differential pulse current response of NHDC was linear with its concentration within the range 0.08 ~ 20 µmol/L, and the linear regression coefficient was 0.9957. The detection limit was as low as 14.2 nmol/L (S/N = 3). In order to further verify the feasibility of the method, it was successfully used to determine the content of NHDC in Chinese medicine, with a satisfactory result, good in accordance with that of high performance liquid chromatography (HPLC).


Assuntos
Chalconas , Cobalto , Técnicas Eletroquímicas , Eletrodos , Limite de Detecção , Estruturas Metalorgânicas , Cobalto/química , Estruturas Metalorgânicas/química , Chalconas/química , Técnicas Eletroquímicas/métodos , Técnicas Eletroquímicas/instrumentação , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/análise , Hesperidina/análogos & derivados , Hesperidina/análise , Hesperidina/química , Polímeros de Fluorcarboneto/química , Oxirredução , Carbono/química , Reprodutibilidade dos Testes , Ferro/química
13.
Small ; : e2403947, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38948958

RESUMO

Converting hierarchical biomass structure into cutting-edge architecture of electrocatalysts can effectively relieve the extreme dependency of nonrenewable fossil-fuel-resources typically suffering from low cost-effectiveness, scarce supplies, and adverse environmental impacts. A cost-effective cobalt-coordinated nanocellulose (CNF) strategy is reported for realizing a high-performance 2e-ORR electrocatalysts through molecular engineering of hybrid ZIFs-CNF architecture. By a coordination and pyrolysis process, it generates substantial oxygen-capturing active sites within the typically oxygen-insulating cellulose, promoting O2 mass and electron transfer efficiency along the nanostructured Co3O4 anchored with CNF-based biochar. The Co-CNF electrocatalyst exhibits an exceptional H2O2 electrosynthesis efficiency of ≈510.58 mg L-1 cm-2 h-1 with an exceptional superiority over the existing biochar-, or fossil-fuel-derived electrocatalysts. The combination of the electrocatalysts with stainless steel mesh serving as a dual cathode can strongly decompose regular organic pollutants (up to 99.43% removal efficiency by 30 min), showing to be a desirable approach for clean environmental remediation with sustainability, ecological safety, and high-performance.

14.
Resusc Plus ; 19: 100665, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38974929

RESUMO

Aim: Compare heart rate assessment methods in the delivery room on newborn clinical outcomes. Methods: A search of Medline, SCOPUS, CINAHL and Cochrane was conducted between January 1, 1946, to until August 16, 2023. (CRD 42021283438) Study Selection was based on predetermined criteria. Reviewers independently extracted data, appraised risk of bias and assessed certainty of evidence. Results: Two randomized controlled trials involving 91 newborns and 1 nonrandomized study involving 632 newborns comparing electrocardiogram (ECG) to auscultation plus pulse oximetry were included. No studies were found that compared any other heart rate measurement methods and reported clinical outcomes. There was no difference between the ECG and control group for duration of positive pressure ventilation, time to heart rate ≥ 100 beats per minute, epinephrine use or death before discharge. In the randomized studies, there was no difference in rate of tracheal intubation [RR 1.34, 95% CI (0.69-2.59)]. No participants received chest compressions. In the nonrandomized study, fewer infants were intubated in the ECG group [RR 0.75, 95% CI (0.62-0.90)]; however, for chest compressions, benefit or harm could not be excluded. [RR 2.14, 95% (CI 0.98-4.70)]. Conclusion: There is insufficient evidence to ascertain clinical benefits or harms associated with the use of ECG versus pulse oximetry plus auscultation for heart rate assessment in newborns in the delivery room.

15.
Artigo em Inglês | MEDLINE | ID: mdl-38977480

RESUMO

BACKGROUND: Preservation of intracochlear structures and residual hearing has become a major concern in modern cochlear implant. Consequently, many efforts have been made to minimize intraoperative trauma, especially while cochlear fenestration and electrode insertion. METHODS: Building on the core concept of "soft surgery", a modified approach, described as diving technique for cochlear implant electrode array insertion is proposed. Steps and technical points are presented with figures, video and review of relevant anatomy. CONCLUSIONS: This novel diving technique is operationally feasible and safe, promising to minimize intraoperative invasion and thus preserve residual hearing in cochlear implant.

16.
Plant Cell Physiol ; 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38978103

RESUMO

The HKT transporter plays an important role for plants in response to salt stress, but the transport property of the soybean HKT transporters at the molecular level is still unclear. Here, using Xenopus oocyte as a heterologous expression system and two-electrode voltage-clamp technique, we identified four HKT transporters, GmHKT1;1, GmHKT1;2, GmHKT1;3, and GmHKT1;4, which all belong to type I subfamily, but having distinct ion transport properties. While GmHKT1;1, GmHKT1;2 and GmHKT1;3 function as Na+ transporters, GmHKT1;1 is less selective against K+ than the two other transporters. Astonishingly, GmHKT1;4, which lacks transmembrane segments and has no ion permeability, is significantly expressed, and its gene expression pattern is different from the other three GmHKTs under salt stress. Interestingly, GmHKT1;4 reduced the Na+/K+ currents mediated by GmHKT1;1. Further study showed that the transport ability of GmHKT1;1 regulated by GmHKT1;4 was related to the structural differences in the first intracellular domain and the fourth repeat domain. Overall, we have identified one unique GmHKT member, GmHKT1;4, which modulates the Na+ and K+ transport ability of GmHKT1;1 via direct interaction. Thus, we have revealed a new type of HKTs interaction model for altering their ion transport properties.

17.
ACS Sens ; 2024 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-38970501

RESUMO

The combination of closed bipolar electrodes (cBPE) with electrochemiluminescence (ECL) imaging has demonstrated remarkable capabilities in the field of bioanalysis. Here, we established a cBPE-ECL platform for ultrasensitive detection of alkaline phosphatase (ALP) and two-dimensional imaging of epidermal growth factor receptor (EGFR). This cBPE-ECL system consists of a high-density gold nanowire array in anodic aluminum oxide (AAO) membrane as the cBPE coupled with ECL of highly luminescent cadmium selenide quantum dots (CdSe QDs) luminophores to achieve cathodic electro-optical conversion. When an enzyme-catalyzed amplification effect of ALP with 4-aminophenyl phosphate monosodium salt hydrate (p-APP) as the substrate and 4-aminophenol (p-AP) as the electroactive probe is introduced, a significant improvement of sensing sensitivity with a detection limit as low as 0.5 fM for ALP on the cBPE-ECL platform can be obtained. In addition, the cBPE-ECL sensing system can also be used to detect cancer cells with an impressive detection limit of 50 cells/mL by labeling ALP onto the EGFR protein on A431 human epidermal cancer cell membranes. Thus, two-dimensional (2D) imaging of the EGFR proteins on the cell surface can be achieved, demonstrating that the established cBPE-ECL sensing system is of high resolution for spatiotemporal cell imaging.

18.
Talanta ; 278: 126513, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38970965

RESUMO

In this work, the electrochemical behavior of the glycosylated flavonoid kaempferitrin was studied, and an electroanalytical methodology was developed for its determination in infusions of Bauhinia forficata using a boron-doped diamond electrode (BDD). The electrochemical behavior of the flavonoid was studied by cyclic voltammetry, and two irreversible oxidation peaks at 0.80 and 1.0 V vs Ag/AgCl were observed. The influence of the pH on the voltammograms was examined, and higher sensitivity was found at pH 7.0. The electrochemical process corresponding to peak 1 at 0.80 V is predominantly diffusion-controlled, as the study shows at varying scan rates. An analytical plot was obtained by square wave voltammetry at optimized experimental conditions (frequency = 100 s-1, amplitude = 90 mV, and step potential = 8 mV) in the concentration range from 3.4 µmol L-1 to 58 µmol L-1, with a linearity of 0.99. The limit of detection and limit of quantification values were 1.0 µmol L-1 and 3.4 µmol L-1, respectively. Three samples of Bauhinia forficata infusions (2 g of sample in 100 mL of water) were analyzed, and the KF values found were 5.0 × 10-4 mol L-1, 3.0 × 10-4 mol L-1, and 7.0 × 10-4 mol L-1, with recovery percentages of 98 %, 106 % and 94 %, respectively. Finally, experiments were performed with two other flavonoids (chrysin and apeginin) to compare and propose an electrochemical oxidation mechanism for kaempferitrin, which was supported by quantum chemical calculations.

19.
Biosens Bioelectron ; 262: 116545, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38971040

RESUMO

Determination of plasma uracil was reported as a method for evaluation of Dihydropyrimidine dehydrogenase (DPD) activity that is highly demanded to ensure the safe administration of 5-fluorouracil (5-FU)-based therapies to cancer patients. This work reports the development of a simple electroanalytical method based on adsorptive stripping square wave voltammetry (AdSWV) at mercury film-coated glassy carbon electrode (MF/GCE) for the highly sensitive determination of uracil in biological fluids that can be used for diagnosis of decreased DPD activity. Due to the formation of the HgII-Uracil complex at the electrode surface, the accuracy of the measurement was not affected by the complicated matrices in biological fluids including human serum, plasma, and urine. The high sensitivity of the developed method results in a low limit of detection (≈1.3 nM) in human plasma samples, falling below the practical cut-off level of 15 ng mL-1 (≈0.14 µM). This threshold concentration is crucial for predicting 5-FU toxicity, as reported in buffer, and ≤1.15% in biological samples), and accuracy (recovery percentage close to 100%).

20.
Int J Biol Macromol ; : 133605, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38971285

RESUMO

The demand for glucose-sensing devices has increased along with the increasing diabetic population. Here, we aimed to construct a system with a glucose oxidase (GOx)-integrated Cu-nanoflower (Cu-NF) as the underlying electrode. This novel system was successfully developed by creating a cross-linked GOx within a Cu-NF matrix, forming a c-GOx@Cu-NF-coated film on a carbon screen-printed electrode (CSPE). A comparison of the stabilities of the cross-linking methods demonstrated enhanced durability, with an activity level of >88 % maintained after approximately 35 days of storage in room temperature buffer. Regarding the ability of the c-GOx@Cu-NF modified CSPE to detect glucose via electrochemical methods, the redox potential gap (ΔE) and peak current increased in the presence of GOx. In comparison to that of glucose, the sensitivity of c-GOx@Cu-NF was approximately 8 times greater than that of GOx@Cu-NF, with a detection limit of 0.649 µM and a linear range of 5-500 µM. It sustained an average relative activity of 80 % over 20 days. After 10 cycles of repeated use, the activity remained above 75 %. In terms of evaluating the electrode's specificity for glucose, the detection rate for individual similar substances was approximately 1 %. The introduction of a crosslinking strategy to Cu-NF, leading to enhanced mechanical stability and conductivity, improved the detection capability. Furthermore, this approach led to increased long-term storage stability and reusability, allowing for specific glucose detection. To our knowledge, this report represents the first demonstration of a c-GOx@Cu-NF system for integrating electrochemical biosensing devices into digital healthcare pathways, offering enhanced sensing accuracy and mechanical stability.

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