Electrochemical sensors developed for gathering microscale chemical information

Miniaturization is a broad trend that has been observed in various areas of technology. As a result of the intensive high tech research efforts of the past few decades in the electronics and telecommunication industries, different tools and technologies have been developed for creating highly structured miniaturized parts and units. These tools and technologies have also been employed for producing special miniaturized units for use in chemical analysis. Miniature sensors, flow micro channels, and detectors are becoming widespread devices in analytical laboratories. The lab-on-a-chip concept is gaining acceptance for a variety of applications. In many different areas of experimental science, researchers endeavor to collect chemical information with high spatial resolution about various subjects. Miniaturized electrochemical sensors and micro or ultramicro electrodes can be used for this purpose. A variety of microelectrodes have been developed and used to collect chemical information in the last few decades. Life scientists, who were studying various biochemical processes inside living tissues with microelectrodes, were pioneers in this work. Recently, a powerful new technique for collecting high resolution chemical information has been devised. This method is known as scanning electrochemical microscopy. Scanning electrochemical microscopy relies on the electrochemical micro-measuring tip. In this short review, the properties of these microelectrodes are discussed briefly, and the types of ion-selective microelectrodes and voltammetric electrodes developed by several research groups for gathering high resolution information are introduced.