Chem. J. Chinese Universities ›› 2019, Vol. 40 ›› Issue (8): 1621.doi: 10.7503/cjcu20180868

• Analytical Chemistry • Previous Articles     Next Articles

Simultaneous Detection of Mercury, Lead and Strontium Ions Based on Conformational Conversion Sensor

ZHOU Yuting,TANG Yujiao,SHAO Shuang,DAI Shiyan,CHENG Guifang(),HE Pingang,FANG Yuzhi   

  1. College of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200241, China
  • Received:2018-12-27 Online:2019-08-10 Published:2019-07-12
  • Contact: CHENG Guifang E-mail:gfcheng@chem.ecnu.edu.cn
  • Supported by:
    † Supported by the National Natural Science Foundation of China(21405049)

Abstract:

A high-sensitive and specific electrochemical biosensor was designed for simultaneous detection of mercury ion(Hg 2+), lead ion(Pb 2+) and strontium ion(Sr 2+) by oligonucleotide conformational transformation. The biosensor was based on porous anodic alumina(PAA) modified with two oligonucleotide aptamers which could capture Hg 2+, Pb 2+ and Sr 2+, respectively. The aptamers can block [Fe(CN)6] 3-/4- ion conduction in the nanochannels of PAA. In the presence of Hg 2+, Pb 2+ and Sr 2+, the aptamers could bend and wrap around those metal ions to make the nanochannel unobstructed, and then, the redox current of [Fe(CN)6] 3-/4- could be increased. When the biosensor eluted with β-mercaptoethanol(βME), 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid(DOTA) and kryptofix 222(KP) successively, the aptamers stretched and released Hg 2+, Pb 2+ and Sr 2+ in sequence, leading to the re-blockage of nanochannel with the decrease of the redox current. The calibration curves of Hg 2+, Pb 2+ and Sr 2+ were obtained in the range of 0.05—2.50 nmol/L, and the detection limits were 0.013, 0.017 and 0.022 nmol/L, respectively. Furthermore, the biosensor is easily constructed, stable and reusable. It is hopeful to apply in the daily monitoring of harmful metal ions in drinking water or environmental water.

Key words: Porous anodic alumina, Hg 2+, Pb 2+, Sr 2+, Biosensor

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