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1.
Mol Biol Rep ; 50(4): 3787-3814, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36692674

RESUMO

Biotic stress is a critical factor limiting soybean growth and development. Soybean responses to biotic stresses such as insects, nematodes, fungal, bacterial, and viral pathogens are governed by complex regulatory and defense mechanisms. Next-generation sequencing has availed research techniques and strategies in genomics and post-genomics. This review summarizes the available information on marker resources, quantitative trait loci, and marker-trait associations involved in regulating biotic stress responses in soybean. We discuss the differential expression of related genes and proteins reported in different transcriptomics and proteomics studies and the role of signaling pathways and metabolites reported in metabolomic studies. Recent advances in omics technologies offer opportunities to reshape and improve biotic stress resistance in soybean by altering gene regulation and/or other regulatory networks. We suggest using 'integrated omics' to precisely understand how soybean responds to different biotic stresses. We also discuss the potential challenges of integrating multi-omics for the functional analysis of genes and their regulatory networks and the development of biotic stress-resistant cultivars. This review will help direct soybean breeding programs to develop resistance against different biotic stresses.


Assuntos
Glycine max , Multiômica , Glycine max/genética , Glycine max/metabolismo , Melhoramento Vegetal , Genômica/métodos , Estresse Fisiológico/genética
2.
Curr Issues Mol Biol ; 44(11): 5440-5473, 2022 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-36354681

RESUMO

Biomass yield and quality are the primary targets in forage crop improvement programs worldwide. Low-quality fodder reduces the quality of dairy products and affects cattle's health. In multipurpose crops, such as maize, sorghum, cowpea, alfalfa, and oat, a plethora of morphological and biochemical/nutritional quality studies have been conducted. However, the overall growth in fodder quality improvement is not on par with cereals or major food crops. The use of advanced technologies, such as multi-omics, has increased crop improvement programs manyfold. Traits such as stay-green, the number of tillers per plant, total biomass, and tolerance to biotic and/or abiotic stresses can be targeted in fodder crop improvement programs. Omic technologies, namely genomics, transcriptomics, proteomics, metabolomics, and phenomics, provide an efficient way to develop better cultivars. There is an abundance of scope for fodder quality improvement by improving the forage nutrition quality, edible quality, and digestibility. The present review includes a brief description of the established omics technologies for five major fodder crops, i.e., sorghum, cowpea, maize, oats, and alfalfa. Additionally, current improvements and future perspectives have been highlighted.

3.
Anal Chem ; 91(12): 7920-7928, 2019 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-31117413

RESUMO

Electrochemical strategies to selectively detect heroin in street samples without the use of complicated electrode modifications were developed for the first time. For this purpose, heroin, mixing agents (adulterants, cutting agent, and impurities), and their binary mixtures were subjected to square wave voltammetry measurements at bare graphite electrodes at pH 7.0 and pH 12.0, in order to elucidate the unique electrochemical fingerprint of heroin and mixing agents as well as possible interferences or reciprocal influences. Adjusting the pH from pH 7.0 to pH 12.0 allowed a more accurate detection of heroin in the presence of most common mixing agents. Furthermore, the benefit of introducing a preconditioning step prior to running square wave voltammetry on the electrochemical fingerprint enrichment was explored. Mixtures of heroin with other drugs (cocaine, 3,4-methylenedioxymethamphetamine, and morphine) were also tested to explore the possibility of their discrimination and simultaneous detection. The feasibility of the proposed electrochemical strategies was tested on realistic heroin street samples from forensic cases, showing promising results for fast, on-site detection tools of drugs of abuse.


Assuntos
Eletroquímica/métodos , Heroína/análise , Heroína/química , Eletroquímica/instrumentação , Eletrodos , Grafite/química , Concentração de Íons de Hidrogênio
4.
Chem Rec ; 19(5): 883-907, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30468273

RESUMO

Electrochemical sensors have drawn significant attention over the last couple of decades because of their ability to improve detection of organic and inorganic analytes found in the field of biotechnology, environmental sciences, medicine, and food quality control. This personal account summarizes the state-of-art research carried out in the construction and evaluation of nanostructured metal oxides and zeolite based electrochemical sensors. Metal oxides and zeolite-based nanomaterials have many unique and extraordinary properties such as tunable redox activity, surface functionalization ability, optimum conductivity, large surface area, biocompatibility and so forth. In this personal account, the current advances in electrochemical sensor applications of metal oxides, zeolite-based nanomaterials, and their nanocomposites are described for the single and simultaneous determination of organic & inorganic contaminants present in water bodies, physiological bio-molecules present in human blood & urine samples, and organic contaminants present in food materials.Moreover, concluding section focuses discussion on the future developments and applications of these materials in various emerging technologies.

5.
Anal Chem ; 89(23): 12756-12763, 2017 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-29111674

RESUMO

In the present work, gold electrodes were modified using a redox-active layer based on dipyrromethene complexes with Cu(II) or Co(II) and a dipodal anion receptor functionalized with dipyrromethene. These modified gold electrodes were then applied for the electrochemical detection of anions (Cl-, SO42-, and Br-) in a highly diluted water solution (in the picomolar range). The results showed that both systems, incorporating Cu(II) as well as Co(II) redox centers, exhibited highest sensitivity toward Cl-. The selectivity sequence found for both systems was Cl- > SO42- > Br-. The high selectivity of Cl- anions can be attributed to the higher binding constant of Cl- with the anion receptor and the stronger electronic effect between the central metal and anion in the complex. The detection limit for the determination of Cl- was found at the 1.0 pM level for both sensing systems. The electrodes based on Co(II) redox centers displayed better selectivity toward Cl- anion detection than those based on Cu(II) centers which can be attributed to the stronger electronic interaction between the receptor-target anion complex and the Co(II)/Co(III) redox centers in comparison to the Cu(II)/Cu(I) system. Applicability of gold electrodes modified with DPM-Co(II)-DPM-AR for the electrochemical determination of Cl- anions was demonstrated using the artificial matrix mimicking human serum.

6.
Lipids Health Dis ; 15(1): 129, 2016 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-27528014

RESUMO

BACKGROUND: Smoking is one of the leading causes of millions of deaths worldwide. During cigarette smoking, most affected and highly exposed cells are the alveolar epithelium and generated oxidative stress in these cells leads to death and damage. Several studies suggested that oxidative stress causes membrane remodeling via Phospholipase A2s but in the case of cigarette smokers, mechanistically study is not yet fully defined. In view of present perspective, we evaluated the involvement of cytosolic phospholipase A2 (cPLA2) IVA as therapeutic target in cigarette smoke induced pathologies in transformed type I and type II alveolar epithelial cells. METHODS: Transformed type I (WI26) and type II (A549) alveolar epithelial cells were used for the present study. Cigarette smoke condensate (CSC) was prepared from most commonly used cigarette (Gold Flake with filter) by the Indian population. CSC-induced molecular changes were evaluated through cell viability using MTT assay, reactive oxygen species (ROS) measurement using 2,7 dichlorodihydrofluorescin diacetate (DCFH-DA), cell membrane integrity using fluorescein diacetate (FDA) and ethidium bromide (EtBr) staining, super oxide dismutase (SOD) levels, cPLA2 activity and molecular involvement of specific cPLA2s at selected 24 h time period. RESULTS: CSC-induced response on both type of epithelial cells shown significantly reduction in cell viability, declined membrane integrity, with differential escalation of ROS levels in the range of 1.5-15 folds and pointedly increased cPLA2 activity (p < 0.05). Likewise, we observed distinction antioxidant potential in these two types of lineages as type I cells had considerably higher SOD levels when compared to type II cells (p < 0.05). Further molecular expression of all cPLA2s increased significantly in a dose dependent manner, specifically cytosolic phospholipase A2 IVA with maximum manifestation of 3.8 folds. Interestingly, CSC-induced ROS levels and cPLA2s expression were relatively higher in A549 cells as compared to WI26 cells. CONCLUSIONS: The present study indicates that among all cPLA2s, specific cPLA2 IVA are the main enzymes involved in cigarette smoke induced anomalies in type I and type II lung epithelial cells and targeting them holds tremendous possibilities in cigarette smoke induced lung pathologies.


Assuntos
Citosol/enzimologia , Pneumopatias/enzimologia , Nicotiana , Fosfolipases A2/análise , Alvéolos Pulmonares/ultraestrutura , Fumaça/efeitos adversos , Células A549 , Linhagem Celular , Células Epiteliais/ultraestrutura , Humanos , Espécies Reativas de Oxigênio/análise
7.
Helicobacter ; 19(2): 116-23, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24237714

RESUMO

BACKGROUND AND AIMS: (14) C-urea breath test ((14) C-UBT) is considered as "gold standard" for detection of active gastric H. pylori infection. However, till date no comparative study using encapsulated and non-encapsulated (14) C-UBT protocols has been conducted in same subjects in identical conditions. We monitored gastric fate of capsule containing (14) C-urea with real time display and compared sensitivities of these protocols at different time points of breath collection. METHODS: Non-encapsulated (14) C-UBT was performed using 74 kBq of (14) C-urea in 100 dyspeptic patients by collecting breath samples at 10, 15 and 20 minutes. Thereafter, within 2 days a gelatin capsule containing (14) C-urea along with 6.0 MBq of (99m) Tc-diethylene triamine penta-acetic acid was administered to each patient for real time display of capsule movement and its fate in gastrointestinal tract by gamma camera. Simultaneously, breath samples were collected for (14) CO2 measurement during image acquisition. RESULTS: Employing non-encapsulated (14) C-UBT, 74 out of 100 dyspeptic patients were found to be H. pylori positive. Discordant (14) C-UBT results were obtained in 4/74 (5.4%) cases using these two protocols. By employing encapsulated and nonencapsulated (14) C-UBT protocols, sensitivities of (14) C-UBT were found to be 90.5 versus 98.6% at 10 and 91.8 versus 97.2% at 15 minutes respectively; while these were 94.6 versus 100, 90.7 versus 98.6 and 83.7 versus 93.2% considering any one, two or all three positive values respectively. CONCLUSIONS: Incomplete/non-resolution of (14) C-urea capsule in stomach during the phase of breath collections appears to decrease sensitivity of encapsulated (14) C-UBT as compared to nonencapsulated protocol for detection of H. pylori infection.


Assuntos
Infecções por Helicobacter/diagnóstico por imagem , Infecções por Helicobacter/diagnóstico , Estômago/microbiologia , Ureia/análise , Adulto , Idoso , Testes Respiratórios/métodos , Radioisótopos de Carbono , Feminino , Gastrite/diagnóstico , Gastrite/diagnóstico por imagem , Gastrite/microbiologia , Infecções por Helicobacter/microbiologia , Helicobacter pylori , Humanos , Masculino , Pessoa de Meia-Idade , Úlcera Péptica/microbiologia , Poliaminas , Cintilografia , Sensibilidade e Especificidade , Estômago/patologia , Úlcera Gástrica/microbiologia , Adulto Jovem
8.
J Nanosci Nanotechnol ; 14(9): 6539-50, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25924298

RESUMO

Nanocrystalline ZSM-5 was prepared by using propyltriethoxysilane as an additive in the conventional ZSM-5 synthesis composition. Materials were characterized by a complementary combination of X-ray diffraction, nitrogen sorption, and Scanning electron microscopy. Transition metal ion exchanged nanocrystalline ZSM-5 (M-Nano-ZSM-5, where M = Cu2+, Ni2+, Co2+, Fe2+, and Mn2+) modified electrodes were constructed for the simultaneous determination of ascorbic acid (AA), dopamine (DA), uric acid (UA), and tryptophan (Trp). Electrochemical studies were carried out by using cyclic voltammetry, linear sweep voltammetry, and chronoamperometry in buffer solution at pH 3.5. Fe-Nano-ZSM-5 modified electrode exhibited excellent electrocatalytic activity with well-separated oxidation peaks towards AA, DA, UA, and Trp in their simultaneous determination. Among the M-Nano-ZSM-5 and transition metal ion-exchanged ZSM-5 (M-ZSM-5) materials investigated in this study, Fe-Nano-ZSM-5 exhibited the highest catalytic activities towards the oxidation of AA, DA, UA, and Trp with good stability, sensitivity, and selectivity. The analytical performance of this sensor was demonstrated for the simultaneous determination of AA, DA, UA, and Trp in blood serum and UA concentration in urine samples.


Assuntos
Ácido Ascórbico/sangue , Dopamina/sangue , Técnicas Eletroquímicas/instrumentação , Ácido Úrico/sangue , Zeolitas/química , Biomarcadores/sangue , Biomarcadores/urina , Técnicas Eletroquímicas/métodos , Eletrodos , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Triptofano/sangue , Ácido Úrico/urina
9.
Anticancer Agents Med Chem ; 23(8): 869-881, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36545721

RESUMO

After cardiovascular disease, cancer is the most common cause of death worldwide. Due to their versatility, heterocyclic compounds play an important role in drug discovery. Medical remedies are constantly being discovered, especially for catastrophic disorders such as cancer. Here, this review is focused on sulphur containing heterocyclic compounds as anticancer agents. Sulphur is found in a variety of vitamin cofactors, sugars, and nucleic acids, and it also plays a function in controlling translation by sulphurating transfer RNA. Sulphur has obtained a lot of interest in the anticancer research medicinal fields. Thiophene derivatives were tested for anti-proliferative activity against breast cancer cells in a recent screening study, and the bulk of chemicals exhibited potent inhibitory effects. In recent years, azoles such as thiazole and thiadiazole structures have gained prominence in cancer research.


Assuntos
Antineoplásicos , Compostos Heterocíclicos , Neoplasias , Humanos , Antineoplásicos/química , Compostos Heterocíclicos/química , Tiazóis/química , Neoplasias/tratamento farmacológico , Enxofre , Relação Estrutura-Atividade
10.
Curr Org Synth ; 20(6): 595-605, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36221870

RESUMO

Cancer is the second most source of cessation of life globally, with 9.6 million expirations at each stage around the globe. The resistance to the current chemotherapies urges researchers to develop new drugs to be available in the market. Among the wide range of drugs synthesized, heterocyclic compounds play a major role due to the abundance of heterocyclic rings in biological substances. In medicinal chemistry, benzimidazole is an important pharmacophore and a privileged structure. This bicyclic compound is made up of the fusion of a six-membered benzene ring and a five-membered imidazole ring with two nitrogen atoms at 1,3-positions. The benzimidazole ring has a great deal of stability. Many strong acids and alkalis do not affect benzimidazoles. The benzene ring of benzimidazole cleaves only under extreme conditions. Except in certain circumstances, the benzimidazole ring is also quite resistant to reduction. It is the most popular nucleus to study because of its wide range of biological functions. The recently developed methods for preparing benzimidazoles, such as condensation of o-phenylene diamines (OPDs) with aldehydes and many others using a wide range of nano, metal-based catalysts under solventfree conditions, are discussed in detail in the current studies.

11.
Curr Org Synth ; 20(4): 376-394, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35538803

RESUMO

Heterocyclic compounds are a class of compounds that is deeply intertwined with biological processes and is found in about 90% of commercially available medicines. They serve a critical function in medicinal chemistry and are focused in the field of medication development for their intensive research due to their broad variety of biological effects because of their intriguing molecular architecture, such as indoles are good candidates for drug development. It is a bicyclic structure consisting of a six-membered benzene ring fused to a five-membered pyrrole ring with several pharmacophores that yield a library of different lead compounds. Human cancer cells have been demonstrated to be inhibited by indoles in the development of new anticancer medicines. This is the first comprehensive review to focus on current methodologies for incorporating indole moiety, with their mechanistic targets as anticancer drugs, in order to shed light on the logical development of indole-based anticancer treatment options with high efficacy. This compiled data may serve as a benchmark for modifying existing ligands in order to design novel potent molecules through excellent yield synthesis techniques.


Assuntos
Antineoplásicos , Compostos Heterocíclicos , Neoplasias , Humanos , Antineoplásicos/química , Neoplasias/tratamento farmacológico , Indóis/química , Compostos Heterocíclicos/uso terapêutico
12.
Chem Biol Drug Des ; 102(2): 357-376, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37009821

RESUMO

Cancer is the second leading cause of death globally, with 9.6 million deaths yearly. As a life-threatening disease, it necessitates the emergence of new therapies. Resistance to current chemotherapies drives scientists to develop new medications that will eventually be accessible. Because heterocycles are so common in biological substances, compounds play a big part in the variety of medications that have been developed. The "Master Key" is the benzimidazole nucleus, which consists of a six-membered benzene ring fused with a five-membered imidazole/imidazoline ring, which is an azapyrrole. One of the five-membered aromatic nitrogen heterocycles identified in American therapies that have been approved by the Food and Drug Administration (FDA). Our results show that benzimidazole's broad therapeutic spectrum is due to its structural isosteres with purine, which improves hydrogen bonding, electrostatic interactions with topoisomerase complexes, intercalation with DNA, and other functions. It also enhances protein and nucleic acid inhibition, tubulin microtubule degeneration, apoptosis, DNA fragmentation, and other functions. Additionally, readers for designing the more recent benzimidazole analogues as prospective cancer treatments.


Assuntos
Antineoplásicos , Antineoplásicos/farmacologia , Antineoplásicos/química , Preparações Farmacêuticas , Benzimidazóis/farmacologia , Benzimidazóis/química , DNA
13.
Trop Gastroenterol ; 33(2): 123-8, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23025059

RESUMO

BACKGROUND: 14C-urea breath test (14C-UBT) is employed as a 'gold standard' technique for the detection of active gastric Helicobacter pylori infection and is recommended as the best option for "test-and-treat" strategy in primary health care centers. AIM: To compare the performance of capsulated and non-capsulated 14C-UBT protocols for the detection of H. pylori infection in patients. METHODS: Fifty eight H. pylori infected patients underwent routine upper GI endoscopy and biopsies were processed for rapid urease test (RUT) and histopathology examination. Capsulated 14C-UBT was done in a novel way by using 74 kBq of 14C-urea along with 6.0 MBq of 99mTc-diethylene triamine penta-acetic acid (99mTc-DTPA) to simultaneously monitor the movement and the fate of ingested capsule after delineating the stomach contour by using 20.0 MBq of 99mTechnetium pertechnetate (99mTcO4-) under dual head gamma camera. Non-capsulated 14C-UBT was performed within 2 days of the previous test and the results of these protocols were compared. RESULTS: In 3 out of 58 H. pylori positive cases (5.17%), 14C-UBT results were found to be negative by using the capsulated method. Interestingly, on monitoring the real time images of the capsule in these cases it was found that misdiagnosis of H. pylori infection occurred mainly due to either rapid transit of the 14C-urea containing capsule from the upper gastric tract or its incomplete resolution in the stomach during the phase of breath collection. CONCLUSION: Use of non-capsulated '4C-UBT protocol appears to be a superior option than the conventional capsule based technique for the detection of H. pylori infection.


Assuntos
Radioisótopos de Carbono , Infecções por Helicobacter/diagnóstico , Helicobacter pylori , Ureia , Testes Respiratórios/métodos , Cápsulas , Reações Falso-Negativas , Infecções por Helicobacter/microbiologia , Humanos , Masculino , Pessoa de Meia-Idade
14.
Chem Biol Drug Des ; 100(3): 419-442, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35713482

RESUMO

Carcinoma, characterized by abnormal growth of cells and tissue, is a ubiquitously leading cause of mortality across the globe due to some carcinogenic factors. Currently, several anticancer agents are commercially available in the global market. However, due to their resistance and cost, researchers are gaining more interest in developing newer novel potential anticancer agents. In the search for new drugs for clinical use, the tetrazole ring system has emerged as an exciting prospect in the optimization studies of promising lead molecules. Among the various heterocyclic agents, tetrazole-containing compounds have shown significant promise in the treatment of a wide range of diseases, particularly cancer. Here, in this review, we focused on several synthetic approaches for the synthesis of tetrazole analogs, their targets for treating cancer along with the biological activity of some of the recently reported tetrazole-containing anticancer agents.


Assuntos
Antineoplásicos , Neoplasias , Humanos , Neoplasias/tratamento farmacológico , Relação Estrutura-Atividade , Tetrazóis/farmacologia
15.
Plants (Basel) ; 10(10)2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34685799

RESUMO

Omics technologies, namely genomics, transcriptomics, proteomics, metabolomics, and phenomics, are becoming an integral part of virtually every commercial cereal crop breeding program, as they provide substantial dividends per unit time in both pre-breeding and breeding phases. Continuous advances in omics assure time efficiency and cost benefits to improve cereal crops. This review provides a comprehensive overview of the established omics methods in five major cereals, namely rice, sorghum, maize, barley, and bread wheat. We cover the evolution of technologies in each omics section independently and concentrate on their use to improve economically important agronomic as well as biotic and abiotic stress-related traits. Advancements in the (1) identification, mapping, and sequencing of molecular/structural variants; (2) high-density transcriptomics data to study gene expression patterns; (3) global and targeted proteome profiling to study protein structure and interaction; (4) metabolomic profiling to quantify organ-level, small-density metabolites, and their composition; and (5) high-resolution, high-throughput, image-based phenomics approaches are surveyed in this review.

16.
Bioelectrochemistry ; 138: 107723, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33360955

RESUMO

We applied a cobalt-porphyrin modified DNA as electrochemical marker, which was attached to nanoparticles, to detect specific DNA sequences. We compare the performance of gold and silver NPs in oligonucleotide sensors to determine if a change in metal will lead to either higher sensitivity or different selectivity, based on the redox behaviour of silver vs. gold. Surprisingly, we find that using either gold or silver NPs yields very similar overall performance. The electrochemical measurements of both types of sensors show the same redox behaviour which is dominated by the cobalt porphyrin, indicating that the electron pathway does not include the NP, but there is direct electron transfer between the porphyrin and the electrode. Both sensors show a linear response in the range of 5 × 10-17-1 × 10-16 M; the limit of detection (LOD) is 3.8 × 10-18 M for the AuNP sensor, and 5.0 × 10-18 M for the AgNP sensor, respectively, which corresponds to the detection of about 20-50 DNA molecules in the analyte. Overall, the silver system results in a better DNA economy and using cheaper starting materials for the NPs, thus shows better cost-effectivness and could be more suitable for the mass-production of highly sensitive DNA sensors.


Assuntos
Técnicas Biossensoriais/métodos , DNA/química , DNA/genética , Ouro/química , Nanopartículas Metálicas/química , Metaloporfirinas/química , Prata/química , Sequência de Bases , Eletroquímica , Limite de Detecção , Modelos Lineares
17.
ACS Appl Mater Interfaces ; 12(40): 45582-45589, 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-32926774

RESUMO

This study describes the fabrication of three-dimensional, open-cell, noble-metal (Au, Ag, and Pt) electrodes that have a complex geometry, i.e., wire mesh, metallic foam, "origami" wire mesh, and helix wire mesh. The electrodes were fabricated using an ultrasonication-assisted electroplating method that deposits a thin, continuous, and defect-free layer of noble metal (i.e., Au, Ag, or Pt) on an inexpensive copper substrate that has the desired geometry. The method is inexpensive, easy to use, and capable of fabricating noble-metal electrodes of complex geometries that cannot be fabricated using established techniques like screen printing or physical vapor deposition. By minimizing the amount of the pure noble metal in the electrodes, their cost drops significantly and could become low enough even for single-use applications; for example, the cost of metal in a Au wire-mesh electrode is $0.007/cm2 of exposed area that is about 400 times lower than that of a wire-mesh electrode composed entirely of Au. The electrodes exhibit an almost identical electrochemical performance to noble-metal electrodes of similar shape composed of bulk noble metal; therefore, these electrodes could replace two-dimensional noble-metal electrodes (e.g., rods, disks, foils) in numerous electroanalytical and electrocatalytical systems or even allow the use of noble-metal electrodes in new applications such as flow-based electrochemical systems. In this study, wire-mesh and metallic foam noble-metal electrodes have been successfully used as working electrodes for the electrocatalytical oxidation of methanol and for the electrochemical detection of redox mediators, lead ions, and nitrobenzene using various electroanalytical techniques.

18.
Spectrochim Acta A Mol Biomol Spectrosc ; 214: 261-268, 2019 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-30785046

RESUMO

Highly crystalline polyethylene glycol (PEG) coated Tb3+ doped ZnS nanoparticles have been synthesized and successfully used for norfloxacin sensing. The crystallographic and morphological analyses of PEG coated Tb3+ doped ZnS nanoparticles were performed by X-ray diffraction and Transmission electron microscopy, respectively. The confirmation of Tb3+ doping in ZnS host matrix was done by emission spectroscopy and energy dispersive X-ray spectroscopy. Further, the interaction of norfloxacin with PEG coated Tb3+ doped ZnS nanomaterials was confirmed by optical analysis: spectrophotometrically and spectrofluorimetrically. Norfloxacin sensing was measured by luminescence intensity which increased with increase in concentration of norfloxacin in range from 2.0 × 10-9-8.0 × 10-7 mol L-1, with its correlation coefficient 0.9991. The detection limit of proposed method was 0.05 × 10-9 mol L-1. The developed luminescence method was successfully applied for the determination of norfloxacin using PEG coated Tb3+ doped ZnS nanoparticles in urine and pharmaceutical samples.


Assuntos
Materiais Revestidos Biocompatíveis/química , Nanoestruturas/química , Norfloxacino , Polietilenoglicóis/química , Sulfetos/química , Térbio/química , Compostos de Zinco/química , Animais , Humanos , Norfloxacino/análise , Norfloxacino/farmacocinética , Norfloxacino/urina , Espectrometria de Fluorescência/métodos
19.
ACS Cent Sci ; 4(12): 1600-1616, 2018 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-30648144

RESUMO

Point-of-care devices were originally designed to allow medical testing at or near the point of care by health-care professionals. Some point-of-care devices allow medical self-testing at home but cannot fully cover the growing diagnostic needs of eHealth systems that are under development in many countries. A number of easy-to-use, network-connected diagnostic devices for self-testing are needed to allow remote monitoring of patients' health. This Outlook highlights the essential characteristics of diagnostic devices for eHealth settings and indicates point-of-care technologies that may lead to the development of new devices. It also describes the most representative examples of simple-to-use, point-of-care devices that have been used for analysis of untreated biological samples.

20.
Chem Commun (Camb) ; 54(79): 11108-11111, 2018 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-30101270

RESUMO

We describe an ultrasensitive electrochemical genosensor based on gold nanoparticles and cobalt-porphyrin functionalised ssDNA probes. The sensitivity at the attomolar concentration level arises from an increased density of redox labels on the electrode surface compared to sensors without NP modification. The electrode detects as few as 23 DNA molecules, approaching single molecule detection.


Assuntos
Técnicas Biossensoriais/métodos , DNA de Cadeia Simples/análise , DNA de Cadeia Simples/química , Ouro/química , Nanopartículas Metálicas/química , Metaloporfirinas/química , Adsorção , Cobalto/química , DNA de Cadeia Simples/genética , Técnicas Eletroquímicas/métodos , Eletrodos , Limite de Detecção , Hibridização de Ácido Nucleico , Oxirredução , Tamanho da Partícula
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