کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6661894 1426559 2018 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A protease-free and signal-on electrochemical biosensor for ultrasensitive detection of lead ion based on GR-5 DNAzyme and catalytic hairpin assembly
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
A protease-free and signal-on electrochemical biosensor for ultrasensitive detection of lead ion based on GR-5 DNAzyme and catalytic hairpin assembly
چکیده انگلیسی
A simple protease-free and signal-on electrochemical biosensor based on GR-5 DNAzyme and catalytic hairpin assembly (CHA) for sensitive lead ion (Pb2+) assay was constructed in this work. In the presence of Pb2+, GR-5 DNAzyme specifically reacted with Pb2+ and cleaved the substrate strand into two free DNA fragments, and one of the two fragments then opened the hairpin capture DNA (Hc) that was assembled on the Au electrode surface and triggered the CHA reaction. Exploiting the CHA strategy, a large number of the hairpin signal DNA (Hs) labeled with two methylene blues (Mbs) were captured on the Au electrode surface and generated an efficient electron transfer, resulting in the dramatic increase of methylene blue current. In this method, Pb2+ could be detected quantitatively in the range of 4 × 10−11-3 × 10−6 M, and the detection limit was as low as 2.7 × 10−11 M (S/N = 3). Experimental results demonstrated that the biosensor was highly specific for Pb2+ and exhibited remarkable improvements of electrochemical analytical performance. This biosensor was also used for the analysis of Pb2+ in the serum sample spiked with Pb2+, and the obtained result in good agreement with the correct values. The excellent performance of the biosensor shows its promising potential for the clinical diagnosis of lead poisoning.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Electroanalytical Chemistry - Volume 816, 1 May 2018, Pages 75-82
نویسندگان
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