The global concern regarding the contamination of soil and environmental matrices by radioactive substances and heavy metals has significant effects on ecosystems and human health. The role of biosensors in identifying these pollutants in soil and associated media is the main topic of this review. Biosensors are useful instruments for environmental monitoring because of their sensitivity, quickness, and selectivity. In this chapter, we discuss the mechanics and most recent developments of various types of biosensors. For biosensors to function properly, sensitivity, selectivity, and stability are essential. New developments like downsizing and the integration of nanomaterials offer improved capabilities. Applications of biosensors in the real world are assessed, and issues with biosensor development, laws, and possibilities for the future are covered. Researchers, environmental scientists, and policymakers can use this review as a resource as it offers information on the current state of biosensors and their applications in detecting radioactive and heavy metals in the environment.