This chapter explores the integration of nanotechnology and biosensors, specifically focusing on nano-biosensors as advanced tools for precision pesticide management in agriculture. Nano-biosensors, analytical devices leveraging nanomaterials, demonstrate remarkable sensitivity, specificity, and efficiency in detecting pesticides, pollutants, and soil conditions. The chapter introduces the fundamentals of nano-biosensors, detailing their components—bioreceptors, nanomaterials, and transducers—and the principles underlying their functionality. Emphasizing applications in pesticide residue detection, real-time monitoring, and sustainable farming, it highlights their role in optimizing pesticide usage, reducing environmental contamination, and enhancing food safety. Advanced nano-pesticides, such as nano-emulsions and polymer-based formulations, are discussed as eco-friendly alternatives. The chapter also addresses challenges like sensitivity, stability, environmental concerns, and ethical considerations, offering insights into regulatory frameworks and cost-effective designs. Case studies illustrate innovations, including graphene-based sensors and enzyme-functionalized systems, showcasing their potential for high-precision, low-cost solutions in modern agriculture. Future perspectives underline the integration of nano-biosensors with Internet of Things (IoT) and artificial intelligence (AI), paving the way for transformative advancements in precision farming and sustainable agriculture.