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论文类型：期刊论文

发表时间：2014-08-01

发表刊物：INTERNATIONAL JOURNAL OF ENVIRONMENTAL ANALYTICAL CHEMISTRY

收录刊物：SCIE、EI

卷号：94

期号：10

页面范围：988-1000

ISSN号：0306-7319

关键字：carbon nanotube; DNAzyme; Microcystin-LR; electrochemical immunoassay

摘要：An electrochemical immunoassay for microcystin-LR (MC-LR) detection was developed using multi-labeled horseradish peroxidase-mimicking DNAzyme on carbon nanotubes (CNTs) as electrocatalyst for signal amplification. CNTs were covalently conjugated to multiple DNAzyme along with MC-LR for a competitive immunoassay. The as-prepared DNAzyme/CNTs/MC-LR biolabel was specifically captured on the electrode surface, and current responses were obtained upon the electro-catalytic reduction of hydrogen peroxide by the captured biolabels. Under optimal conditions, the electro-catalytic current decreased linearly with the increase amount of MC-LR in the range from 0.01 to 7.0 mu g L-1. The linear regression equation was I (mu A) = 12.96 - 1.48 X ([MC-LR]) (mu g L-1), with a correlation coefficient of 0.989. The limit of detection of MC-LR was 2.31 ng L-1. Application of the immunoassay method and LC/MS/MS method for MC-LR determination on spiked reservoir water gave recovery range of 91.7-105.2% and 94.0-105.0%, respectively. The resulting versatile immunoassay exhibited high sensitivity, good precision and satisfactory reproducibility, which could have vast potential in routine water quality monitoring for various environmental toxins.