Vapor sensors based on functionalized carbon nanotubes (NTs) have shown great promise, with high sensitivity conferred by the reduced dimensionality and exceptional electronic properties of the NT. Critical challenges in the development of NT-based sensor arrays for chemical detection include the demonstration of reproducible fabrication methods and functionalization schemes that provide high c...

Optical techniques for chemical analysis are well established and sensors based on these techniques are now attracting considerable attention because of their importance in applications such as environmental monitoring, biomedical sensing, and industrial process control. On the other hand, flow injection analysis (FIA) is advisable for the rapid analysis of microliter volume samples and can be ...

Microfabrication processes for chemical and biochemical sensors are reviewed. Standard processing steps originating from semiconductor technology are detailed, and specific micromachining steps to fabricate three-dimensional mechanical structures are described. Fundamental chemical sensor principles are briefly abstracted and corresponding state-of-the-art examples of microfabricated chemical s...

Partially coating perpendicularly aligned carbon nanotube arrays with an appropriate polymer thin film along their tube length provides a novel concept for developing new sensors of high sensitivity, good selectivity, and excellent environmental stability for the detection of a broad class of chemical vapors with low power consumption. The absorption and desorption of chemical vapors by the pol...

Several possibilities for new fiber-optic sensors are proposed that are based on two-photon spectroscopic techniques. Examples are chemical sensors, including multiplexed sensors, as well as magnetidelectric sensors. The development of a compact, low-cost fiber-optic method for tbe accurate measurement of timdfrequency is also proposed.

We have explored the abilities of all-electronic DNA-carbon nanotube (DNA-NT) vapor sensors to discriminate very similar classes ofmolecules.We screened hundreds of DNA-NT devices against a panel of compounds chosen because of their similarities. We demonstrated that DNA-NT vapor sensors readily discriminate between series of chemical homologues that differ by single methyl groups. DNA-NT devic...

There are many types of electrical signal that can be sensed from liquid solution. Among them conductivity signal is more suitable than voltage signal for the study of liquid. Thus, we choose conductivity as the target sense signal for the study of taste sensors. We developed a chemical sensors array with seven chemical sensors. There are two groups in the designed sensors. The first group is m...

One dimensional polyaniline nanowire is an electrically conducting polymer that can be used as an active layer for sensors whose conductivity change can be used to detect chemical or biological species. In this review, the basic properties of polyaniline nanowires including chemical structures, redox chemistry, and method of synthesis are discussed. A comprehensive literature survey on chemires...

The National Institute of Standards and Technology, an agency of the U.S. Department of Commerce, in cooperation with the 6th International Meeting on Chemical Sensors Steering Committee, held a symposium on chemical sensor science and technology on July 22-25, 1996 in Gaithersburg, Maryland. The meeting was attended by 427 persons from 27 countries. A total of 299 oral presentations and poster...