A Sensitive DNAzyme-Based Chiral Sensor for Lead Detection

A DNAzyme-based sensor for the determination and quantification of lead ions (Pb(2+)) 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(2+) concentration was obtained ranging from 0.05 ng∙mL(−1) to 10 ng∙mL(−1) with a limit of detection (LOD) of 0.02 ng∙mL(−1). 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(2+) in water.