共查询到20条相似文献,搜索用时 15 毫秒
1.
Jiadi Sun Ying Gan Tao Liang Shuqi Zhou Xinyi Wang Hao Wan Ping Wang 《Current Opinion in Electrochemistry》2019
Heavy-metal pollution has attracted intensive attention from the public because of the severe threats of heavy metals to the ecosystem and human health. Ultralow concentration of heavy metals in aquatic environment leads to the urgent needs of sensitive approaches for heavy-metal detection. Electrochemical DNA biosensors present outstanding superiority in convenience, selectivity, and sensitivity compared with conventional methods. To achieve the ultralow detection limit, efforts have been made to implement signal enhancement strategies to develop electrochemical DNA biosensors with enhanced sensing performance. This review focuses on the recent progress in signal enhancement strategies applied to electrochemical DNA biosensors for heavy-metal-ion detection including nicking enzyme–assisted amplification, the utilization of core–shell nanoparticles, and nanocomposites modification. 相似文献
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F.R.R. Teles 《Talanta》2008,77(2):606-623
Biosensors have witnessed an escalating interest nowadays, both in the research and commercial fields. Deoxyribonucleic acid (DNA) biosensors (genosensors) have been exploited for their inherent physico-chemical stability and suitability to discriminate different organism strains. The main principle of detection among genosensors relies on specific DNA hybridization, directly on the surface of a physical transducer. This review covers the main DNA immobilization techniques reported so far, new micro- and nanotechnological platforms for biosensing and the transduction mechanisms in genosensors. Clinical applications, in particular, demand large-scale and decentralized DNA testing. New schemes for DNA diagnosis include DNA chips and microfluidics, which couples DNA detection with sample pretreatment under in vivo-like hybridization conditions. Higher sensitivity and specificity may arise from nanoengineered structures, like carbon nanotubes (CNTs) and DNA/protein conjugates. A new platform for universal DNA biosensing is also presented, and its implications for the future of molecular diagnosis are argued. 相似文献
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Sergiy Varvarenko Volodymyr Samaryk Nataliya Nosova Nataliia Puzko Roman Taras Ihor Tarnavchyk Andriy Voronov Ananiy Kohut Stanislav Voronov 《Macromolecular Symposia》2010,298(1):72-78
Summary: Results of a study on polymer surface modification using heterofunctional polyperoxides are presented. A prognostic model of the polymer surface modifier efficiency was developed on the basis of obtained data. It was shown that implementation of demands to the macromolecule composition during development of new peroxide-containing modifiers in combination with sufficient peroxide group reactivity increased efficiency of the polymer surface modification. 相似文献
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Eshkenazi I Sacks V Neufeld T Rishpon J 《Applied biochemistry and biotechnology》2000,89(2-3):217-230
Novel electrochemical cells based on a microflow system combined with amperometric enzyme electrodes were developed and served
for quantitative determination of various compounds, such as organophosphates and lactose. The resulting biosensors are selective
and efficient owing to immobilization of the sensing elements on the electrodes. The sensors are easy to operate, and the
procedures are rapid, accurate, reproducible, and inexpensive, requiring neither special skills and training nor complicated
instrumentation. The use of a microflow cell ensures the continuous flux of a new substrate, thus preventing the accumulation
or adsorption of products to the electrode. Miniaturization of the sensor has two main advantages: (1) it is easy to carry
and therefore can be used outdoors as well, and (2) it allows working with low volumes of compounds and reagents, which is
highly important when dealing with hazardous compounds. 相似文献
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医用高分子材料表面的润滑改性进展 总被引:4,自引:0,他引:4
综述了医用高分子材料表面的润滑改性方法,对影响表面润滑性的因素进行了讨论,简述了材料表面润滑性的测定方法,润滑机理及润滑表面的形态,概述了表面润滑的医用高分子材料在临床中的应用。 相似文献
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Gennady Evtugyn Anastasia Mingaleva Ekaterina Stoikova Sergei Eremin 《Analytica chimica acta》2003,479(2):125-134
Simple and sensitive DNA sensors have been developed on a base on graphite screen-printed electrodes modified with DNA and enzymes. Cholinesterase and peroxidase immobilized by treatment with glutaraldehyde were used for the detection of human DNA antibodies of systemic lupus erythematosus and bronchial asthma patients. The amperometric signal was measured at +680 mV versus Ag/AgCl for DNA-cholinesterase sensor and −150 mV for DNA-peroxidase sensor 5 min after the injection of acethylthiocholine and hydroquinone, respectively. The addition of serum samples results in the sharp decrease of the signal due to the formation of DNA-antibody adducts followed by the suppression of the access of substrate to the enzyme active site. Sulfonamide medicines suppress the DNA-antibody interaction due to the competitive binding along DNA minor grooves. DNA sensor labeled with peroxidase showed the linear calibration range of 5×10−9 to 7×10−5 mol l−1 of sulfamethoxazole and of 5×10−8 to 1×10−4 mol l−1 of sulfathiazole. 相似文献
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Current research activity in biosensors 总被引:11,自引:0,他引:11
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Marli L. Moraes Ubirajara P. Rodrigues Filho Osvaldo N. OliveiraJr. Marystela Ferreira 《Journal of Solid State Electrochemistry》2007,11(11):1489-1495
The layer-by-layer technique was exploited to immobilize the enzyme uricase onto indium tin oxide substrates coated with a
layer of Prussian Blue. Uricase layers were alternated with either poly(ethylene imine) or poly(diallyldimethylammoniumchloride),
and the resulting films were used as amperometric biosensors for uric acid. Biosensors with optimum performance had a limit
of detection of 0.15 μA μmol l−1 cm−2 with a linear response between 0.1 and 0.6 μM of uric acid, which is sufficient for use in clinical tests. Bioactivity was
preserved for weeks, and there was negligible influence from interferents, as detection was carried out at 0.0 V vs saturated
calomel electrode.
This paper is dedicated to the memory of Francisco C. Nart. 相似文献
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We developed a method to graft a tripeptide (glutathione) onto 5-hydroxy-1,4-naphthoquinone, an electropolymerizable molecule. The resulting thin conducting polymer presents a well-defined and stable electroactivity in neutral buffered solution, due to the embedded quinone group, and is able to covalently graft amino-modified DNA probe strands. It is shown that the bioelectrode presents positive current change following DNA hybridization. This makes a “signal-on” direct electrochemical DNA sensor. The results were obtained with low target concentration (50 nM) and the selectivity is excellent as a single-mismatch sequence can be discriminated from the full-complementary target. 相似文献
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Rivas GA Rubianes MD Rodríguez MC Ferreyra NF Luque GL Pedano ML Miscoria SA Parrado C 《Talanta》2007,74(3):291-307
The aim of this review is to summarize the most relevant contributions in the development of electrochemical (bio)sensors based on carbon nanotubes in the last years.Since the first application of carbon nanotubes in the preparation of an electrochemical sensor, an increasing number of publications involving carbon nanotubes-based sensors have been reported, demonstrating that the particular structure of carbon nanotubes and their unique properties make them a very attractive material for the design of electrochemical biosensors.The advantages of carbon nanotubes to promote different electron transfer reactions, in special those related to biomolecules; the different strategies for constructing carbon nanotubes-based electrochemical sensors, their analytical performance and future prospects are discussed in this article. 相似文献
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The enormous potential of biosensors in medical diagnostics has motivated scientists to develop newer innovative tools and advance biosensing technologies. The use of cell, organelles, nucleotides, aptamers, antibodies, affibodies, proteins, peptides, molecules, and printed polymers, merged with nanotechnology, offers excellent tools to prepare highly sensitive and advanced biosensors. Therefore, the current decade has witnessed a rapid surge in the fabrication of different nanomaterial-based biosensors. Among them, carbon nanomaterials (CNMs) have emerged highly attractive in the fabrication of both electrochemical and electrochemiluminescence (ECL) biosensors. On one hand, CNMs bear prominent electrical conductivity, large surface area to immobilize adequate amount of biomolecules, an enhanced loading capacity, improved biocompatibility, and active site for electrochemical reaction. Additionally, CNMs could be chemically modified for the covalent coupling with the biomolecules. On the other hand, both electrochemical and ECL biosensors allow for cost-effective, rapid, and real-time detection with excellent sensitivity and selectivity, with the capability of integrating different biomolecules and CNMs on the same chip. However, currently there is not a single review, which includes CNM-based electrochemical and ECL biosensors' current progress and trends. Therefore, this review intends to survey the current progress and future trends in CNM-based electrochemical and ECL biosensors. 相似文献
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Electrochemical glucose enzyme biosensors have been prepared on carbon film electrodes made from carbon film electrical resistors. Evaluation and characterisation of these electrodes in phosphate buffer saline solution has been carried out with and without pretreatment by cycling in perchloric acid or at fixed applied potential. Both pretreatments led to a reduction in the carbon surface oxidation peak and enabled better detection of hydrogen peroxide in the pH range of 5-7. Glucose oxidase enzyme was immobilised on the carbon surface by mixing with glutaraldehyde, bovine serum albumin and with and without Nafion. The performance of these two types of electrode was similar, that containing Nafion being more physically robust. Linear ranges were up to around 1.5 mM, with detection limits 60 μM, and pretreatment of the carbon film electrode at a fixed potential of +0.9 V versus SCE for 5 min was found to be the most beneficial. Michaelis-Menten constants between 5 mM and 10 mM were found under the different experimental conditions. Coating the immobilised enzyme layer with a thin layer of Nafion was found to give similar results in the determination of glucose to mixing it but with benefits against interferences for the analysis of complex matrices, such as wine. Potentialities, for a short-term-use or disposable sensors, are indicated. 相似文献
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Electrochemical DNA biosensors based on platinum nanoparticles combined carbon nanotubes 总被引:1,自引:0,他引:1
Platinum nanoparticles were used in combination with multi-walled carbon nanotubes (MWCNTs) for fabricating sensitivity-enhanced electrochemical DNA biosensor. Multi-walled carbon nanotubes and platinum nanoparticles were dispersed in Nafion, which were used to fabricate the modification of the glassy carbon electrode (GCE) surface. Oligonucleotides with amino groups at the 5′ end were covalently linked onto carboxylic groups of MWCNTs on the electrode. The hybridization events were monitored by differential pulse voltammetry (DPV) measurement of the intercalated daunomycin. Due to the ability of carbon nanotubes to promote electron-transfer reactions, the high catalytic activities of platinum nanoparticles for chemical reactions, the sensitivity of presented electrochemical DNA biosensors was remarkably improved. The detection limit of the method for target DNA was 1.0 × 10−11 mol l−1. 相似文献
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Walter Vastarella Vito Rosa Carlo Cremisini Livia Della Seta Maria Rita Montereali 《International journal of environmental analytical chemistry》2013,93(10-11):689-699
Organophosphorous (OP) insecticides reveal acute toxicity because of their capability to affect the nervous system through the inhibition of acetyl cholinesterase function in regulating the neurotransmitter acetylcholine. The present work shows an example of an easy to be handled inhibition electrochemical biosensor, based on thick film technology for low cost production of screen printed electrodes. Anti-cholinesterase activity in specific fruits was determined measuring the inhibition of acetyl cholinesterase enzyme owing to the presence of OP pesticides. Paraoxon was taken as reference pesticide for each measurement. The main fluidic critical parameters were investigated under flow injection analysis, through the comparison of different enzymatic immobilisation methods. Analytical features were evaluated as a function of experimental parameters. The analytical detection was developed in a three step procedure and the pesticides content was measured in strawberries samples taken from the local market. The separation between the acetyl cholinesterase inhibition and the electrochemical detection with the choline oxidase biosensor decreases the total analysis time, allowing improvements in reproducibility and stability of the system. A comparison with reference materials and standard analytical procedures for pesticides will be required in the future for evaluating the reliability of the method. 相似文献
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低温等离子体对聚合物多孔膜的亲水化改性 总被引:8,自引:0,他引:8
综述了低温等离子体在聚合物多孔膜表面亲水化改性领域的研究与应用进展。在简要介绍等离子体技术的原理、方法的基础上,讨论了Ar、He、O2、N2、CO2、H2O、NH2和SO2等非反应性和反应性气体的等离子体表面处理,烷基醇、烷基胺、烯丙基醇和烯丙基胺等饱和及不饱和单体的等离子体沉积聚合,以及烯类单体的等离子体引发的接枝聚合等等离子体方法,对膜表面和膜孔壁的化学组成和形态结构、膜亲水性的获得及其时效性、膜水通量和蛋白质抗污染性等方面的影响。 相似文献