A comprehensive multi-technique electrochemical study and TEM insights into an WO3-based Pb(II) Apta-sensor in lake water

Abstract

Lead ion (Pb2+), a hazardous heavy metal ion, is a typical contaminant in natural water resources, demanding utmost importance for appropriate monitoring to assess environmental health. This study, presents a comprehensive innovative approach towards developing an aptamer-based electrochemical sensor for sensitive and selective Pb2+detection in lake water. The sensorʼs core component consists of a vaccancy-rich tungsten trioxide modified glassy carbon electrode functionalized with lead-specific aptamers, exhibiting linear response towards increasing Pb²⁺ ion concentrations. Notably, it displays excellent selectivity, distinguishing the target from other common interfering ions with an LOD of 3 pM and 0.75 pM using DPV and EIS methods, respectively. The sensitivity obtained using EIS is 5.26 nM−1 cm−2, and the sensor has a shelf life of 30 days. The sensor represents a promising tool for environmental monitoring, offering cost-effective, rapid, and highly sensitive detection of lead ions in lake water, thereby aiding in the preservation and protection of freshwater ecosystems and human health. Furthermore, to achieve a reliable insight into the sensor development protocol, the transducing material is thoroughly characterized with TEM, and the STEM-EDS mapping is employed as a unique qualitative method, providing additional reliability towards the aptasenor evaluation. The HRTEM analyses are performed for local lattice constants evaluation, suggesting local strains, thereby modulation of the electrical properties.