oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
DNA-Metallodrugs Interactions Signaled by Electrochemical Biosensors: An Overview  [PDF]
Mauro Ravera,Graziana Bagni,Marco Mascini,Domenico Osella
Bioinorganic Chemistry and Applications , 2007, DOI: 10.1155/2007/91078
Abstract: The interaction of drugs with DNA is an important aspect in pharmacology. In recent years, many important technological advances have been made to develop new techniques to monitor biorecognition and biointeraction on solid devices. The interaction between DNA and drugs can cause chemical and conformational modifications and, thus, variation of the electrochemical properties of nucleobases. The propensity of a given compound to interact with DNA is measured as a function of the decrease of guanine oxidation signal on a DNA electrochemical biosensor. Covalent binding at N7 of guanine, electrostatic interactions, and intercalation are the events that this kind of biosensor can detect. In this context, the interaction between a panel of antitumoral Pt-, Ru-, and Ti-based metallodrugs with DNA immobilized on screen-printed electrodes has been studied. The DNA biosensors are used for semiquantitative evaluation of the analogous interaction occurring in the biological environment.
Biosensors for Pesticide Detection: New Trends  [PDF]
Audrey Sassolas, Beatriz Prieto-Simón, Jean-Louis Marty
American Journal of Analytical Chemistry (AJAC) , 2012, DOI: 10.4236/ajac.2012.33030
Abstract: Due to the large amounts of pesticides commonly used and their impact on health, prompt and accurate pesticide analysis is important. This review gives an overview of recent advances and new trends in biosensors for pesticide detection. Optical, electrochemical and piezoelectric biosensors have been reported based on the detection method. In this review biosensors have been classified according to the immobilized biorecognition element: enzymes, cells, antibodies and, more rarely, DNA. The use of tailor-designed biomolecules, such as aptamers and molecularly imprinted polymers, is reviewed. Artificial Neural Networks, that allow the analysis of pesticide mixtures are also presented. Recent advances in the field of nanomaterials merit special mention. The incorporation of nanomaterials provides highly sensitive sensing devices allowing the efficient detection of pesticides.
Electrochemical biosensors – principles and applications
Miroslav Pohanka,Petr Skladal
Journal of Applied Biomedicine , 2008,
Abstract: The first scientifically proposed as well as successfully commercialized biosensors were those based on electrochemical sensors for multiple analytes. Electrochemical biosensors have been studied for a long time. Currently, transducers based on semiconductors and screen printed electrodes represent a typical platform for the construction of biosensors. Enzymes or enzyme labeled antibodies are the most common biorecognition components of biosensors. The principles of, and the most typical applications for electrochemical biosensors are described in this review. The relevant systems are divided into three types according to the operating principle governing their method of measurement : potentiometric, amperometric and impedimetric transducers, and the representative devices are described for each group. Some of the most typical assays are also mentioned in the text.
Electrochemical Based Biosensors  [PDF]
Chung Chiun Liu
Biosensors , 2012, DOI: 10.3390/bios2030269
Abstract: This editorial summarizes the general approaches of the electrochemical based biosensors described in the manuscripts published in this Special Issue. Electrochemical based biosensors are scientifically and economically important for the detection and early diagnosis of many diseases, and they will be increasing used and developed in the coming years. The importance of the selection of recognition processes, fabrication techniques and biosensor materials will be introduced.
Electrochemical biosensors in pharmaceutical analysis
Gil, Eric de Souza;Melo, Giselle Rodrigues de;
Brazilian Journal of Pharmaceutical Sciences , 2010, DOI: 10.1590/S1984-82502010000300002
Abstract: given the increasing demand for practical and low-cost analytical techniques, biosensors have attracted attention for use in the quality analysis of drugs, medicines, and other analytes of interest in the pharmaceutical area. biosensors allow quantification not only of the active component in pharmaceutical formulations, but also the analysis of degradation products and metabolites in biological fluids. thus, this article presents a brief review of biosensor use in pharmaceutical analysis, focusing on enzymatic electrochemical sensors.
Microfabricated Electrochemical Cell-Based Biosensors for Analysis of Living Cells In Vitro  [PDF]
Jun Wang,Chengxiong Wu,Ning Hu,Jie Zhou,Liping Du,Ping Wang
Biosensors , 2012, DOI: 10.3390/bios2020127
Abstract: Cellular biochemical parameters can be used to reveal the physiological and functional information of various cells. Due to demonstrated high accuracy and non-invasiveness, electrochemical detection methods have been used for cell-based investigation. When combined with improved biosensor design and advanced measurement systems, the on-line biochemical analysis of living cells in vitro has been applied for biological mechanism study, drug screening and even environmental monitoring. In recent decades, new types of miniaturized electrochemical biosensor are emerging with the development of microfabrication technology. This review aims to give an overview of the microfabricated electrochemical cell-based biosensors, such as microelectrode arrays (MEA), the electric cell-substrate impedance sensing (ECIS) technique, and the light addressable potentiometric sensor (LAPS). The details in their working principles, measurement systems, and applications in cell monitoring are covered. Driven by the need for high throughput and multi-parameter detection proposed by biomedicine, the development trends of electrochemical cell-based biosensors are also introduced, including newly developed integrated biosensors, and the application of nanotechnology and microfluidic technology.
Utilization of Electrochemical Sensors and Biosensors in Biochemistry and Molecular Biology  [PDF]
Vojtech Adam,Rene Kizek
Sensors , 2008, DOI: 10.3390/s8106125
Abstract: Editorial note concerning the "Utilization of Electrochemical Sensors and Biosensors in Biochemistry and Molecular Biology" special issue.
Recent Updates of DNA Incorporated in Carbon Nanotubes and Nanoparticles for Electrochemical Sensors and Biosensors  [PDF]
Umasankar Yogeswaran,Soundappan Thiagarajan,Shen-Ming Chen
Sensors , 2008, DOI: 10.3390/s8117191
Abstract: Innovations in the field of electrochemical sensors and biosensors are of much importance nowadays. These devices are designed with probes and micro electrodes. The miniaturized designs of these sensors allow analyses of materials without damaging the samples. Some of these sensors are also useful for real time analysis within the host system, so these sensors are considered to be more advantageous than other types of sensors. The active sensing materials used in these types of sensors can be any material that acts as a catalyst for the oxidation or reduction of particular analyte or set of analytes. Among various kinds of sensing materials, deoxyribonucleic acid (DNA), carbon nanotubes (CNTs) and nanoparticles have received considerable attraction in recent years. DNA is one of the classes of natural polymers, which can interact with CNTs and nanoparticles to form new types of composite materials. These composite materials have also been used as sensing materials for sensor applications. They have advantages in characteristics such as extraordinary low weight and multifunctional properties. In this article, advantages of DNA incorporated in CNT and nanoparticle hybrids for electrochemical sensors and biosensors are presented in detail, along with some key results noted from the literature.
Applications of Nanomaterials in Electrochemical Enzyme Biosensors  [PDF]
Huihui Li,Songqin Liu,Zhihui Dai,Jianchun Bao,Xiaodi Yang
Sensors , 2009, DOI: 10.3390/s91108547
Abstract: A biosensor is defined as a kind of analytical device incorporating a biological material, a biologically derived material or a biomimic intimately associated with or integrated within a physicochemical transducer or transducing microsystem. Electrochemical biosensors incorporating enzymes with nanomaterials, which combine the recognition and catalytic properties of enzymes with the electronic properties of various nanomaterials, are new materials with synergistic properties originating from the components of the hybrid composites. Therefore, these systems have excellent prospects for interfacing biological recognition events through electronic signal transduction so as to design a new generation of bioelectronic devices with high sensitivity and stability. In this review, we describe approaches that involve nanomaterials in direct electrochemistry of redox proteins, especially our work on biosensor design immobilizing glucose oxidase (GOD), horseradish peroxidase (HRP), cytochrome P450 (CYP2B6), hemoglobin (Hb), glutamate dehydrogenase (GDH) and lactate dehydrogenase (LDH). The topics of the present review are the different functions of nanomaterials based on modification of electrode materials, as well as applications of electrochemical enzyme biosensors.
Applications of Ionic Liquids in Electrochemical Sensors and Biosensors  [PDF]
Virendra V. Singh,Anil K. Nigam,Anirudh Batra,Mannan Boopathi,Beer Singh,Rajagopalan Vijayaraghavan
International Journal of Electrochemistry , 2012, DOI: 10.1155/2012/165683
Abstract: Ionic liquids (ILs) are salt that exist in the liquid phase at and around 298?K and are comprised of a bulky, asymmetric organic cation and the anion usually inorganic ion but some ILs also with organic anion. ILs have attracted much attention as a replacement for traditional organic solvents as they possess many attractive properties. Among these properties, intrinsic ion conductivity, low volatility, high chemical and thermal stability, low combustibility, and wide electrochemical windows are few. Due to negligible or nonzero volatility of these solvents, they are considered “greener” for the environment as they do not evaporate like volatile organic compounds (VOCs). ILs have been widely used in electrodeposition, electrosynthesis, electrocatalysis, electrochemical capacitor, lubricants, plasticizers, solvent, lithium batteries, solvents to manufacture nanomaterials, extraction, gas absorption agents, and so forth. Besides a brief discussion of the introduction, history, and properties of ILs the major purpose of this review paper is to provide an overview on the advantages of ILs for the synthesis of conducting polymer and nanoparticle when compared to conventional media and also to focus on the electrochemical sensors and biosensors based on IL/composite modified macrodisk electrodes. Subsequently, recent developments and major strategies for enhancing sensing performance are discussed. 1. Introduction ILs are a class of materials which have attracted many scientists as holding a great promise for green chemistry applications [1–3]. Paul Walden gave a definition to ILs that is still acknowledged today [4]. They are “materials composed of cations and anions, those melt around 100°C or below as an arbitrary temperature limit.” This definition identifies the difference from molten salts that have also been known for a long time and are inorganic salts with high melting temperatures [5]. A typical IL has a bulky organic cation (e.g., N-alkylpyridinium, N-N′-dialkylimidazolium) that is weakly coordinated to an organic or inorganic anion, such as , , , , and . The big difference in the size of a bulky cation and a small anion does not allow packing of lattice, which happens in many inorganic salts; instead, the ions are disorganized. This results in that some of these salts remain liquid at the room temperature [2]. ILs are liquid electrolytes composed entirely of ions. Due to the high ionic conductivity, nonvolatility, low vapor pressure, thermal stability, hydrophobicity, and wide electrochemical window that ionic liquids possess, these compounds have
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.