Surfactant-Based Electrochemical Devices for the Determination of Pesticides

Surfactants possessing surface-active properties have been extensively employed in analytical chemistry for over a century. Their chemically dual structure stems from the presence of both polar and nonpolar groups. The polar portions impart hydrophilic characteristics, while the nonpolar segments exhibit hydrophobic/lipophilic properties. Classification of surfactants is based on the charge of their hydrophilic part, resulting in categories such as cationic, anionic, non-ionic, and zwitterionic. Furthermore, they can be derived from synthetic or natural sources, forming two distinct classes. Surfactants have found application in electrochemical analysis, enhancing the sensitivity by serving as electrolyte components and electrode modifiers. By increasing the electron transfer rate between the electrode surface and the analyte, surfactants enable obtaining low detection limits. Currently, surfactant-based electrochemical sensors or biosensors find utility in various fields, including the food industry, drug analysis, and examination of drug release profiles. In this chapter, the applications of surfactants in pesticide analysis using electrochemical sensors and biosensors are discussed. After a brief overview of surfactant properties and synthesis, selected studies from the past decade are presented in tables along with experimental conditions and key validation parameters.