Chemical sensors for portable, handheld field instruments

摘要

A review of three commonly used classes of chemical sensorntechnologies as applicable to implementation in portable, handheld fieldninstruments is presented. Solid-state gas and chemical sensors have longnbeen heralded as the solution to a wide variety of portable chemicalnsensing system applications. However, advances in optical sensingntechnology have reduced the size of supporting infrastructure to bencompetitive with their solid-state counterparts. Optical, solid-state,nand hybrid arrays of sensors have application for portable instruments,nbut issues of insufficient selectivity and sensitivity continue tonhamper the widespread introduction of these miniaturized sensors fornsolving chemical sensing problems in environments outside thenlaboratory. In this article, we evaluate three of the major classes ofncompact chemical sensors for portable applications: (solid-state)nchemiresistors, (solid-state) CHEMFETs, and (optical) surface plasmonnresonance sensors (SPR). These sensors are evaluated and reviewed,naccording to the current state of research, in terms of their ability tonoperate at low-power, small-size, and relatively low-cost innenvironments, with numerous interferents and variable ambient conditions