An Electrochemical Aptasensor for Pb²⁺ Detection Based on Metal-Organic-Framework-Derived Hybrid Carbon

A new double-shelled carbon nanocages material was synthesized and developed an aptasensor for determining Pb²⁺ in aqueous solution. Herein, nanoporous carbon materials derived from core-shell zeolitic imidazolate frameworks (ZIFs) demonstrated excellent electrochemical activity, stability, and high specificity surface area, consequently resulting in the strong binding with aptamers. The aptamer strands would be induced to form G-quadruplex structure when Pb²⁺ was introduced. Under optimal conditions, the aptasensor exhibited a good linear relationship of Pb²⁺ concentration ranging from 0.1 to 10 μg L^-1 with the detection limits of 0.096 μg L^-1. The feasibility was proved by detecting Pb²⁺ in spiked water samples and polluted soil digestion solution. The proposed aptasensor showed excellent selectivity and reproducibility, indicating promising applications in environmental monitoring.