A Sensitive DNAzyme-Based Chiral Sensor for Lead Detection.

A DNAzyme-based sensor for the determination and quantification of lead ions (Pb) has been established, which combines the recognition and catalysis of DNAzyme with the optical properties of nanomaterials. Circular dichroism (CD) signals were obtained by a DNAzyme-based assembly of asymmetric silver nanoparticle (AgNPs) dimers. A good linear relationship between CD signals and Pb concentration was obtained ranging from 0.05 ng∙mL to 10 ng∙mL with a limit of detection (LOD) of 0.02 ng∙mL. The specificity of this sensor in lead ion detection was excellent, and a satisfactory recovery was obtained in the analysis of tap water samples. The proposed technique possesses both high sensitivity and good specificity, giving it great potential for the analysis of Pb in water.