New Materials in Electochemical Sensors for Pesticides Monitoring

Pesticides are substances or mixtures thereof, natural or synthetic, formulated to prevent or control any species of plants or pests. The term pesticide includes substances intended for use as plant -growth regulators, defoliants or desiccants. Once a pesticide is introduced into the environment, either through an application, removal or a spill, it is influenced by processes, such as adsorption, transfer, breakdown and degradation, which determine their persistence, movement and its final fate. In recent years the growing awareness of the risk associated with intensive use of pesticides has led to a more critical attitude towards the use of agrochemicals. At the same time, many national environmental agencies have been involved in the development of regulations to eliminate or severely restrict the use and production of a number of pesticides. However in the third millennium, pesticides will continue to play an important role in plant diseases and pest management. Even in developed countries, where farmers are shifting from subsistence agriculture to modern agriculture, pesticide use may increase at a high rate. Therefore, their use should be optimized, bearing in mind the safety to producers and consumers as well as the environmental impact. Monitoring and exposure data are critical to accurately determine the impact of pesticides on human health and environment. The analytical methods, faster and more cost-effective, can facilitate the collection of data concerning particular target pesticides that may impact on human health and the environment. Advances in miniaturization and microfabrication technology have led to the development of sensitive and selective electrochemical devices for field-based and in situ environmental monitoring (Pellicer et al., 2010). Electrochemical sensors can provide fast, reliable and cost-effective measurement and monitoring methods. Hanrahan et al. (2004) examine the role electrochemical sensors play in environmental monitoring, focusing on recent technological advances in terms of microfabrication, analytical improvements and remote communication capabilities, including also microfluidic integration and submersible devices for remote, continuous monitoring. The development of in situ electrochemical devices requires proper attention to major issues including reversibility, long-term stability, specificity and changes in natural conditions that may affect the response of interest.