Calixarene-based Sensing Agents

摘要

The development of new and more efficient means of performing real-time monitoring of chemical and biochemical species through the use of sensors is among the most significant challenges facing modern science. The problems involved are multi-faceted requiring a broad understanding of many areas ranging from synthesis to thin layer deposition and surface analysis technologies, and involving computer-based data acquisition and signal processing. The nature of the component used to generate the diagnostic signal is central to determining the overall performance of any chemical sensor as this will largely, though not absolutely, define the critical characteristics of the device, namely its selectivity, lifetime and response time. However, despite much effort over the past 30 or so years, the number of really efficient individual sensors remains disappointingly small, probably reflecting the ad hoc nature of the design and synthesis of potential sensing agents. To be fair, the difference between a really efficient sensing agent and a hopeless one is very difficult to predict since, on a molecular basis, the processes which together define the overall preference for a target substance, in preference to all interferents, interact in subtle ways. However, recent improvements in the power of computer systems and refinements in the algorithms used to minimise molecular energies in solution have enabled more accurate predictions of structures and conformations to be made, and it is now possible in advance to probe how a sensor might interact in a dynamic sense with certain target species in different solvents. In addition, the large amount of information now available should enable statistical tools and pattern recognition techniques to provide more insight into the factors which determine selectivity.