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Sensing Platform (sensing + platform)
Selected AbstractsSensitive Biomimetic Sensor Based on Molecular Imprinting at Functionalized Indium Tin Oxide ElectrodesELECTROANALYSIS, Issue 16 2007Na Gao Abstract We initially report an electrochemical sensing platform based on molecularly imprinted polymers (MIPs) at functionalized Indium Tin Oxide Electrodes (ITO). In this research, aminopropyl-derivatized organosilane aminopropyltriethoxysilane (APTES), which plays the role of functional monomers for template recognition, was firstly self-assembled on an ITO electrode and then dopamine-imprinted sol was spin-coated on the modified surface. APTES which can interact with template dopamine (DA) through hydrogen bonds brought more binding sites located closely to the surface of the ITO electrode, thus made the prepared sensor more sensitive for DA detection. Potential scanning is presented to extract DA from the modified film, thus DA can rapidly and completely leach out. The affinity and selectivity of the resulting biomimetic sensor were characterized using cyclic voltammetry (CV). It exhibited an increased affinity for DA over that of structurally related molecules, the anodic current for DA oxidation depended on the concentration of DA in the linear range from 2×10,6 M to 0.8×10,3 M with a correlation coefficient of 0.9927. In contrast, DA-templated film prepared under identical conditions on a bare ITO showed obviously lower response toward dopamine in solution. It should be noted that potential scanning is a very effective approach for DA extraction, and surface modification of the electrochemical transducer with functional monomers is responsible for the development of MIPs-based highly sensitive biomimetic sensor. [source] A Graphene Nanoprobe for Rapid, Sensitive, and Multicolor Fluorescent DNA AnalysisADVANCED FUNCTIONAL MATERIALS, Issue 3 2010Shijiang He Abstract Coupling nanomaterials with biomolecular recognition events represents a new direction in nanotechnology toward the development of novel molecular diagnostic tools. Here a graphene oxide (GO)-based multicolor fluorescent DNA nanoprobe that allows rapid, sensitive, and selective detection of DNA targets in homogeneous solution by exploiting interactions between GO and DNA molecules is reported. Because of the extraordinarily high quenching efficiency of GO, the fluorescent ssDNA probe exhibits minimal background fluorescence, while strong emission is observed when it forms a double helix with the specific targets, leading to a high signal-to-background ratio. Importantly, the large planar surface of GO allows simultaneous quenching of multiple DNA probes labeled with different dyes, leading to a multicolor sensor for the detection of multiple DNA targets in the same solution. It is also demonstrated that this GO-based sensing platform is suitable for the detection of a range of analytes when complemented with the use of functional DNA structures. [source] Gas Sensors: Room-Temperature Gas Sensing Based on Electron Transfer between Discrete Tin Oxide Nanocrystals and Multiwalled Carbon Nanotubes (Adv. Mater.ADVANCED MATERIALS, Issue 24 200924/2009) Hybrid nanostructures consisting of multiwalled carbon nanotubes (CNTs) uniformly coated with SnO2 nanocrystals can be used as a novel gas sensing platform, exhibiting high sensitivity to low-concentration gases (NO2, H2, and CO) at room temperature, report Junhong Chen and co-workers on p. 2487. The hybrid nanomaterial provides a new opportunity to engineer sensing devices through electronic transfer between the nanocrystals and the CNT. [source] Design of Gold Nanoparticle-Based Colorimetric Biosensing AssaysCHEMBIOCHEM, Issue 15 2008Weian Zhao Abstract Gold nanoparticle (AuNP)-based colorimetric biosensing assays have recently attracted considerable attention in diagnostic applications due to their simplicity and versatility. This Minireview summarizes recent advances in this field and attempts to provide general guidance on how to design such assays. The key to the AuNP-based colorimetric sensing platform is the control of colloidal AuNP dispersion and aggregation stages by using biological processes (or analytes) of interest. The ability to balance interparticle attractive and repulsive forces, which determine whether AuNPs are stabilized or aggregated and, consequently, the color of the solution, is central in the design of such systems. AuNP aggregation in these assays can be induced by an "interparticle-crosslinking" mechanism in which the enthalpic benefits of interparticle bonding formation overcome interparticle repulsive forces. Alternatively, AuNP aggregation can be guided by the controlled loss of colloidal stability in a "noncrosslinking-aggregation" mechanism. In this case, as a consequence of changes in surface properties, the van der Waals attractive forces overcome interparticle repulsive forces. Using representative examples we illustrate the general strategies that are commonly used to control AuNP aggregation and dispersion in AuNP-based colorimetric assays. Understanding the factors that play important roles in such systems will not only provide guidance in designing AuNP-based colorimetric assays, but also facilitate research that exploits these principles in such areas as nanoassembly, biosciences and colloid and polymer sciences. [source] Hierarchical Models in Environmental ScienceINTERNATIONAL STATISTICAL REVIEW, Issue 2 2003Christopher K. Wikle Summary Environmental systems are complicated. They include very intricate spatio-temporal processes, interacting on a wide variety of scales. There is increasingly vast amounts of data for such processes from geographical information systems, remote sensing platforms, monitoring networks, and computer models. In addition, often there is a great variety of scientific knowledge available for such systems, from partial differential equations based on first principles to panel surveys. It is argued that it is not generally adequate to consider such processes from a joint perspective. Instead, the processes often must be considered as a coherently linked system of conditional models. This paper provides a brief overview of hierarchical approaches applied to environmental processes. The key elements of such models can be considered in three general stages, the data stage, process stage, and parameter stage. In each stage, complicated dependence structure is mitigated by conditioning. For example, the data stage can incorporate measurement errors as well as multiple datasets with varying supports. The process and parameter stages can allow spatial and spatio-temporal processes as well as the direct inclusion of scientific knowledge. The paper concludes with a discussion of some outstanding problems in hierarchical modelling of environmental systems, including the need for new collaboration approaches. Résumé Les systèmes environnementaux sont complexes. Ils incluent des processus spatio-temporels trés complexes, interagissant sur une large variété d'échelles. II existe des quantités de plus en plus grandes de données sur de tels processus, provenant des systèmes d'information géographiques, des plateformes de télédétection, des réseaux de surveillance et des modèles informatiques. De plus, il y a souvent une grande variété de connaissance scientifique disponible sur de tels systémes, depuis les équations différentielles partielles jusqu'aux enquétes de panels. II est reconnu qu'il n'est généralement pas correct de considerer de tels processus d'une perspective commune. Au contraire, les processus doivent souvent étre examinés comme des systèmes de modèles conditionnels liés de manière cohérente. Cet article fournit un bref aperçu des approches hiérachiques appliquées aux processus environnementaux. Les éléments clés de tels modèles peuvent étre examinés à trois étapes principales: l'étape des donnèes, celle du traitement et celle des paramètres. A chaque étape, la structure complexe de dépendance est atténuée par le conditionnement. Par exemple, le stade des données peut incorporer des erreurs de mesure ainsi que de multiples ensembles de données sous divers supports. Les stades du traitement et des paramétres peuvent admettre des processus spatiaux et spatio-temporels ainsi que l'inclusion directe du savoir scientifique. L'article conclut par une discussion de quelques problèmes en suspens dans la modélisation hiérarchique des systèmes environnementaux, incluant le besoin de nouvelles approches de collaboration. [source] Research Priorities for Neotropical Dry Forests,BIOTROPICA, Issue 4 2005G. Arturo Sánchez-Azofeifa ABSTRACT Our understanding of the human and biophysical dimensions of tropical dry forest change and its cumulative effects is still in the early stages of academic discovery. The papers in this special section on Neotropical dry forests cover a wide range of sites and problems ranging from the use of multispectral and hyperspectral remote sensing platforms to the impact of hurricanes on tropical dry forest regeneration. Here, we present to the scientific community the results of a workshop on which research priorities for tropical dry forests were discussed. This discussion focuses on the need to develop linkages between remote sensing, ecological, and social science research. The incorporation of social sciences into ecological research could contribute dramatically to our understandings of tropical dry forests by providing important contextual information to ecologists, and by helping to develop an important science,policy,public nexus on which environmental management can succeed. RESUMEN El conocimiento actual de las dimensiones humanas y biofísicas de los cambios en los bosque secos tropicales y sus efectos acumulativos esta en las etapas iniciales del descubrimiento académico. En este articulo, introducimos una serie de artículos científicos asociados a este número especial sobre bosques secos en los Neotropicos. Estos artículos provienen de una distribución muy variada de sitios en las Américas y van desde las aplicaciones de sensores multi- e hiperspectrales, hasta el estudio del efecto que los huracanes causan en la regeneración de los bosques secos. Presentamos a la comunidad científica los resultados de un taller dirigido a la discusión de aquellas prioridades de investigación en bosques secos. La discusión se enfoca a lo largo de los vínculos que se necesitan entre percepción remota, ecología y ciencias sociales. La incorporación las ciencias sociales dentro de la investigación ecológica podría contribuir dramáticamente al entendimiento de los bosque secos tropicales, así como tienen len a posibilidad de ayudar en el desarrollo de vínculos importantes entre ciencia y política dirigida al manejo de los recursos presentes en este importante ecosistema. [source] | |||||||||||||