Electrochemical biosensors have shown significant progress in the detection of hazardous chemicals used in agriculture. These biosensors are designed to detect toxic substances, such as pesticides and heavy metals, in water. They offer improved stability, enhanced analytical performance, and integration with microfluidic devices for environmental remote sensing. Recent research focuses on the use of nanomaterials to enhance sensor performance, with special emphasis on the detection of toxic species. These biosensors play an important role in precision agriculture by providing sustainable solutions for the effective detection of toxic agents. In addition, electrochemical bio-nanosensors have been developed for detecting mycotoxins and pesticide residues in food, providing convenient and sensitive detection methods.