title: A turn-off fluorescent biosensor for the rapid and sensitive detection of uranyl ion based on molybdenum disulfide nanosheets and specific DNAzyme.
abstract: A novel fluorescent biosensor for detecting uranyl ion (UO2(2+)) in aqueous environment has been developed based on the specific recognition of DNAzyme and the fluorescence quenching ability of molybdenum disulfide (MoS2) nanosheets. The DNAzyme contains a DNA enzyme strand and a 6-carboxylfluorescein (FAM)-labeled DNA substrate strand. We demonstrated that MoS2 nanosheets have low affinity to the substrate-enzyme complex DNAzyme. Whereas, in the presence of UO2(2+), UO2(2+) can specifically cleave DNAzyme to release FAM-labeled single-strand DNA and the released FAM-labeled single-strand DNA can be firmly adsorbed on the surface of MoS2 nanosheets, which resulted in an obvious decrease of fluorescence intensity. This provided a sensing platform for the rapid, simple and sensitive fluorescent detection of UO2(2+). By using the sensing platform, a sensitive and selective fluorescent method for the rapid detection of UO2(2+) has been developed. In comparison with previous biosensor, the proposed method has obvious analytical advantage such as relatively high sensitivity and good stability, short analytical time and low cost. It can be used to detect as low as 2.14 nM of UO2(2+) in aqueous environment with a recovery of 96-102% and a RSD<5% (n=6). The success of this study provides a promising alternative for the rapid and on-site detection of UO2(2+) in environmental monitoring.
authors: Key Lab of Analysis and Detection for Food Safety of Ministry of Education, Fujian Provincial Key Lab of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China; College of Pharmacy, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China.
authors: HongYan
authors: H
authors: Zhang
authors: Key Lab of Analysis and Detection for Food Safety of Ministry of Education, Fujian Provincial Key Lab of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China.
authors: YaJuan
authors: Y
authors: Ruan
authors: Key Lab of Analysis and Detection for Food Safety of Ministry of Education, Fujian Provincial Key Lab of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China.
authors: Ling
authors: L
authors: Lin
authors: Fujian Environmental Radiation Supervision Station, Fuzhou, Fujian 350012, China.
authors: Minggui
authors: M
authors: Lin
authors: Key Lab of Analysis and Detection for Food Safety of Ministry of Education, Fujian Provincial Key Lab of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China.
authors: Xiaoxue
authors: X
authors: Zeng
authors: Key Lab of Analysis and Detection for Food Safety of Ministry of Education, Fujian Provincial Key Lab of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China.
authors: Zhiming
authors: Z
authors: Xi
authors: Key Lab of Analysis and Detection for Food Safety of Ministry of Education, Fujian Provincial Key Lab of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China. Electronic address: fengfu@fzu.edu.cn.
authors: FengFu
authors: F
authors: Fu
mesh_terms: D015374:Biosensing Techniques; D021881:DNA, Catalytic / Q000737:chemistry*; D005453:Fluorescence; D053758:Nanoparticles / Q000737:chemistry*; D012680:Sensitivity and Specificity; D017974:Uranium Compounds / Q000032:analysis*
chemical_list: D021881:DNA, Catalytic; D017974:Uranium Compounds
keywords: DNAzyme; Fluorescent biosensor; Molybdenum disulfide; Uranyl ion