Fluorescent detection of Cu (II) ions based on DNAzymatic cascaded cyclic amplification
- PDF / 1,144,513 Bytes
- 9 Pages / 595.276 x 790.866 pts Page_size
- 76 Downloads / 191 Views
ORIGINAL PAPER
Fluorescent detection of Cu (II) ions based on DNAzymatic cascaded cyclic amplification Jingjing Tian 1,2,3 & Zaihui Du 1,2,3 & Longjiao Zhu 1,2,3 & Xiangli Shao 1,2 & Xiangyang Li 4 & Wentao Xu 1,2,3 Received: 25 February 2020 / Accepted: 7 July 2020 # Springer-Verlag GmbH Austria, part of Springer Nature 2020
Abstract A fluorescent biosensor based on the cascaded cyclic amplification-lighted copper nanoparticles has been developed, optimized, and validated. In the double-modular cascaded cyclic amplification, a DNAzymatic cyclic amplification unit transforms metal ion signal to specific DNA sequences, and a linear/exponential integrated amplification unit converts as-prepared DNA codes to identical thymine (T)-rich DNA templates. T-rich scaffolds can induce the generation of red fluorescent copper nanoparticles, with fluorescence emission at 625 nm upon the excitation at 340 nm, as signal vehicles for quantitative detection of metal ions. Copper ions, selected as the model target, could be detected in a wide linear range from 10 to 104 nM depending on the increased fluorescent intensity, and the detection limit is 5.6 ± 0.52 nM (n = 3) within 40 min, which is 4 orders of magnitude lower than the limits set in drinking water. In the detection of Cu2+ in real tap and lake water, the results between inductively coupled plasma mass spectrometry (ICP-MS) and our proposed biosensor were consistent, illustrating the practicability of the fabricated method. In summary, the established fluorescent biosensor compensates the deficiency of immunoassays failing to analyze metal ions, broadens ranges of biomarkers responding to cleaved DNAzymes, provides an open platform sensing different metal ions, and meets the increasing need for the ultrasensitive detection in the field of food safety, environmental monitoring, and medical diagnosis. Keywords DNA nanotechnology . Copper nanoparticles . Cascaded cyclic amplification . Biosensor
Introduction Analytical science is intended to detect wide ranges of targets with satisfactory performance [1]. Rapid detection techniques are of great importance for sustainable development and Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00604-020-04430-4) contains supplementary material, which is available to authorized users. * Wentao Xu [email protected] 1
Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing 100083, China
2
Key Laboratory of Functional Dairy, Ministry of Education, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
3
Key Laboratory of Safety Assessment of Genetically Modified Organism (Food Safety), Ministry of Agriculture, Beijing 100083, China
4
Food Science and Engineering College, Beijing University of Agriculture, Beijing 102206, China
human health [2]. Thereinto, antibody (Ab)-based immunoassays and enzyme-linked immunosorbent assays play a crucial role in detectin
Data Loading...
