Design of DNAzyme Catalytic Amplification-based Biosensing Platform for Colorimetric Detection of Lead (II)

A novel DNAzyme catalytic amplification biosensing platform has been developed for the colorimetric detection of lead ions (Pb2+) by utilizing the catalytic cleavage of 8–17 DNAzyme and the catalytic redox of horseradish peroxidase (HRP)-mimicking DNAzyme. The effects of K+ concentration, pH and incubation time of the detection system were investigated. A good linear relationship between ABTS absorbance and Pb2+ concentration in the range of 5–100 nM with a detection limit of 3 nM was found. In addition, an outstanding selectivity of the sensor for Pb2+ against other environmentally related metal ions was observed.