期刊
BIOSENSORS & BIOELECTRONICS
卷 25, 期 8, 页码 1994-1998出版社
ELSEVIER ADVANCED TECHNOLOGY
DOI: 10.1016/j.bios.2010.01.014
关键词
Mercury(II) ion; Lead(II) ion interference; Thrombin-binding aptamer; Unmodified gold nanoparticles; Colorimetry
类别
资金
- National Natural Science Foundation of China [20890022]
- National Key Basic Research Development Project of China [2010CB933602]
- Project of Chinese Academy of Sciences [KICX2-YW-H09]
A colorimetric assay for the determination of mercury(II) (Hg2+) in the presence of lead(II) (Pb2+) was demonstrated with unmodified gold nanoparticles (AuNPs) as probes and 15-met thrombin-binding aptamer (TBA, 5'-GGTTGGTGTGGTTGG-3') as sensing elements. Upon the addition of Hg2+ or Pb2+, TBA consisting of six thymidine units and nine guanosine units interacted specifically with both ions to form a hairpin-like or a quadruplex structure, respectively. As a result, these conformation changes facilitated the salt-induced AuNP aggregation. Subsequently, to eliminate Pb2+ interference in the determination of Hg2+, a novel technique by the use of a characteristic wavelength of aggregated AuNPs instead of the universal masking agent of Pb2+ (2,6-pyridinedicarboxylic acid, PDCA) was herein proposed. A comparison of the absorption spectra of the aggregated AuNPs in the presence of Hg2+ and Pb2+ showed that the characteristic wavelength of the aggregated AuNPs (800 nm) facilitated the determination of Hg2+ in the presence of Pb2+. The calibration curve showed that the absorbance value at 800 nm increased linearly over the Hg2+ concentration range of 0.39-8.89 mu M with a limit of detection of 200 nM. Then, the assay was successfully employed to determine Hg2+ in several water samples. (c) 2010 Elsevier B.V. All rights reserved.
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