Remote Sensing

Remote sensing is the ability to acquire information about an object or phenomenon without physically contacting the object or place from which this information is obtained. Remote sensing is a fast-developing field, which makes it possible to monitor secluded or inaccessible areas. Sensing can be passive, where energy is collected or active whereby energy is emitted by the sensor and perturbs the sensing environment. Remote electrochemical sensing has many advantages since the electrochemical sensors can be made relatively small and cheap and, nevertheless, are highly sensitive and in many cases possess also high selectivity and robustness. Transduction of the electrochemical response into an electrical signal that can be transmitted over long distances is inherently part of the electrochemical sensor. The major challenges in remote electrochemical systems are sampling and delivery of the sample to the detector. This usually requires introducing a flow system. Flow systems not only enable the automation of the measurement and ensure relatively easy data collection, but also simplify the entire process in comparison with a static process, which contains various stages of liquid replacements and mixing. Electrochemical methods are known for their high sensitivity, thus enabling the measurement of very low concentration employing small volumes. These make coupling between electrochemical measurements and flow systems ideal for remote sensing. This chapter describes the concepts of remote sensing in general and remote electrochemical sensing in particular. We review the different approaches and studies dealing with remote electrochemical sensing including voltammetry, potentiometry and other techniques. Conclusions of the advantages and disadvantages of remote electrochemical sensing are discussed and perspectives of this type of sensing are suggested.