Environmental Applications: Sensors and Sensor Systems: Overview Nanotech-Enabled Sensors and Sensor Systems

摘要

The introduction and incorporation of nanomaterials and nanotechnology offers the potential for revolutionary transformations in the capabilities of sensors and sensor systems. Nanoscale sensor technologies rely on the unique physical and chemical properties conferred by their size. Intelligent use of such materials will permit the design of light, compact, low power, and exquisitely sensitive devices. Even old detection methods are being enhanced with the use of nanoscale materials. New sensor designs will exploit the inherent, often unique chemical and physical properties of nanoscale materials, such as engineered band structures, electrical conduction, mechanical resonance, quantum effects, optical properties, large surface to volume ratio, and small mass. For example, the large surface to volume ratio of a nanoparticles translates into large changes in the electrical conductivity or mechanical resonance of the nanostructure when very small quantities of analyte adsorb on its surface. The ability to manipulate the size of the particles, and especially their surface chemistry, therefore makes them amenable to designed modifications and optimization for particular analytical tasks. These qualities also make sensors based on nanotechnology especially well suited for arrays with different chemistries and transduction mechanisms, thus enhancing their selectivity and ability to discriminate analytes in complex chemical environments. These characteristics suggest that sensors will be increasingly flexible and customizable to specific tasks as research provides suites of suitable chemistries and designs built upon common architectures. Such a sensor can be based on varying numbers of these structures, from a single particle, such as a carbon nanotube, to an amalgamation of many particles, e.g. metal beads coated with an organic layer to form a 2-dimensional layer. Other sensors rely less on the specific size-dependent properties, but still benefit from using nanoscale particles optimized for other desirable device properties, e.g. low power consumption.