The new era of SAW devices

摘要

When surface acoustic wave (SAW) instruments were last reviewed by Analytical Chemistry (2003, 75, 355 A-358 A), expectations were high that the technology would continue to evolve as an analytical technique for environmental, security, and process monitoring. However, the scenario has unfolded a bit differently than expected because competing analytical technologies such as fluorescent labeling, ion mobility spectroscopy, and enzyme-based electrochemical methods have been difficult to displace. Military applications remain critical, but a SAW device is often one unit in a multisensor hybrid system designed for several analytical tasks. For example, a single security monitoring device must search for chemical, biological, and nuclear hazards simultaneously. SAW devices have been incorporated into a commercial electronic nose that conducts analyses by fast GC. The electronic nose simulates animal olfactory responses and can be programmed for specific monitoring tasks, such as testing fragrances or detecting explosives. Electronic noses react to multiple analytes simultaneously, producing characteristic patterns that can be converted into high-resolution visual images or other convenient formats.