Electrochemical Biosensors for Detection of Pesticides and Heavy Metal Toxicants in Water: Recent Trends and Progress

The release of chemicals into water systems has resulted in pollution in many parts of the world, threatening human health and aquatic ecosystems. Sources of chemical discharge include industry, agricultural, wastewater treatment plants, and stormwater overflows. To combat water pollution, the European Union has introduced several directives that set concentration limits for chemicals in drinking water, surface water, and groundwater. To meet these limits, it is essential that rapid, reliable, and sensitive analytical detection systems be developed and put into use. This Review presents the progress made in the development of electrochemical biosensors for environmental toxicants (pesticides and heavy metals) over the past seven years (2014-2020). For those unfamiliar with this field of research, the concept of a biosensor is introduced followed by a critical evaluation of their performance in detecting the toxicants. Current challenges are discussed as well as potential avenues for future research, including the demands for enhanced analytical performance, improved biosensor stability and shelf life, and greater integration with microfluidic devices and wireless database technologies for remote environmental sensing applications. We believe that this Review will be beneficial and enhance awareness and appreciation of the role that electrochemical biosensors can play in protecting our environment and water resources.