Detection of Pb2+ in Aqueous Solution by Using a DNA modified Microcantilever.
We developed a novel Pb2+ sensor based on a microcantilever that was modified with a specific Pb2+ dependent DNAzyme molecule. This microcantilever sensor could detect Pb2+ sensitively and selectively in an aqueous solution. Upon complexation with Pb2+ the DNAzyme duplex unwinded and formed a G quadruplex conformation, which led to an increase of repulsion between the DNAzyme molecules and a subsequent bending of the microcantilever. This microcantilever sensor could be regenerated, flowing through a strong Pb2+ chelator, 1,4,7,10 tetraazacyclododecane 1,4,7,10 tetraacetic acid. The detection limit of the microcantilever sensor for Pb2+ ions is as low as 10 8 M. The microcantilever sensor also exhibited a high selectivity to Pb2+ over other metal ions such as Mg2+ Fe3+ Zn2+ Ca2+ and Cd2+
Analytical sciences the international journal of the Japan Society for Analytical Chemistry