Analytical Sciences


Abstract − Analytical Sciences, 32(10), 1065 (2016).

Detection of Pb2+ in Aqueous Solution by Using a DNA-modified Microcantilever
Rong-Peng PENG,*,**,*** Ling-Bao XING,* Xiao-Jun WANG,* Cheng-juan WU,* Bin CHEN,* Hai-Feng JI,*** Li-Zhu WU,* and Chen-Ho TUNG*
*Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences and Graduate University of Chinese Academy of Sciences, Beijing 100190, China
**College of Chemistry, Nanchang University, Nanchang 330031, Jiangxi, China
***Department of Chemistry, Drexel University, Philadelphia, Pennsylvania, 19010, USA
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+.