Nanomaterials play a crucial role in addressing global challenges like environmental pollution, resource scarcity, and climate change. The advancements emphasize the development of nanomaterials that are environmentally friendly, renewable, and effective for environmental applications. Bio-based nanomaterials represent a class of nanomaterials sourced from renewable biological origins, including plants, animals, microbes, or their waste products. Bio-based nanomaterials possess unique properties, including biocompatibility and functional diversity, enabling their application across various sectors, such as environmental monitoring, food packaging, biomedicine, and agriculture. Energy harvesting using nanomaterials entails the application of nanostructured substances to capture and transform ambient energy into usable electrical power. Energy can be derived from various sources, including solar, thermal, mechanical (vibration or motion), and chemical energy. Recent advancements in sustainable nanomaterials for precision and environmental monitoring demonstrate considerable potential in tackling environmental issues. Recent advancements have resulted in the development of efficient, scalable, and flexible nanomaterial-based systems capable of detecting and mitigating pollutants with high accuracy and sensitivity. The primary advantages consist of high efficiency in energy capture and conversion, scalability from small sensors to large systems, and the ability to integrate into flexible devices for diverse applications.