Sensing lead ions in water: a comprehensive review on strategies and sensor materials

It is well-known fact that elevated lead ions (Pb²⁺), the third most toxic among heavy metal ions in aqueous systems, pose a threat to human health and aquatic ecosystems when they exceed permissible limits. Pb²⁺ is commonly found in industrial waste and fertilizers, contaminating water sources and subsequently entering the human body, causing various adverse health conditions. Unlike being expelled, Pb²⁺ accumulates within the body, posing potential health risks. The harmful impact of presence of Pb²⁺ in water have prompted researchers to diligently work toward maintaining water quality. Recognizing the importance of Pb²⁺, this review article makes a sincere and effective effort to address the issues associated with Pb²⁺. This overview article gives insights into various sensing approaches to detect Pb²⁺ in water using different sensing materials, including 2-dimensional materials, thiols, quantum dots, and polymers. Herein, different sensing approaches such as electrochemical, optical, field effect transistor-based, micro-electromechanical system-based, and chemi resistive are thoroughly explained. Field effect transistor-based and chemiresistive work on similar principles and are compared on the basis of their fabrication processes and sensing capabilities. In conclusion, future directions for chemiresistive sensors in Pb²⁺ detection are proposed, emphasizing their simplicity, portability, straightforward functionality, and ease of fabrication. Notably, it sheds light on various thiol and ligand compounds and coupling strategies utilized in Pb²⁺ detection. This comprehensive study is expected to benefit individuals engaged in Pb²⁺ detection.