title: Magnetic beads-based DNAzyme recognition and AuNPs-based enzymatic catalysis amplification for visual detection of trace uranyl ion in aqueous environment.
abstract: We herein developed a novel biosensor for the visual detection of trace uranyl ion (UO2(2+)) in aqueous environment with high sensitivity and specificity by using DNAzyme-functionalized magnetic beads (MBs) for UO2(2+) recognition and gold nano-particles (AuNPs)-based enzymatic catalysis oxidation of TMB (3,3',5,5'-tetramethylbenzidine sulfate) for signal generation. The utilization of MBs facilitates the magnetic separation and collection of sensing system from complex sample solution, which leads to more convenient experimental operation and more strong resistibility of the biosensor to the matrix of sample, and the utilization of AuNPs-based enzymatic catalysis amplification greatly improved the sensitivity of the biosensor. Compared with the previous DNAzyme-based UO2(2+) sensors, the proposed biosensor has outstanding advantages such as relative high sensitivity and specificity, operation convenience, low cost and more strong resistibility to the matrix of sample. It can be used to detect as low as 0.02 ppb (74 pM) of UO2(2+) in aqueous environment by only naked-eye observation and 1.89 ppt (7.0 pM) of UO2(2+) by UV-visible spectrophotometer with a recovery of 93-99% and a RSD ≤ 5.0% (n=6) within 3h. Especially, the visual detection limit of 0.02 ppb (74 pM) is much lower than the maximum allowable level of UO2(2+) (130 nM) in the drinking water defined by the U.S. Environmental Protection Agency (EPA), indicating that our method meets the requirement of rapid and on-site detection of UO2(2+) in the aqueous environment by only naked-eye observation.
authors.affiliation: 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.forename: Hongyan
authors.initials: H
authors.lastname: Zhang
authors.affiliation: 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.forename: Ling
authors.initials: L
authors.lastname: Lin
authors.affiliation: 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.forename: Xiaoxue
authors.initials: X
authors.lastname: Zeng
authors.affiliation: 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.forename: Yajuan
authors.initials: Y
authors.lastname: Ruan
authors.affiliation: China National Center for Food Safety Risk Assessment, Beijing 100022, China.
authors.forename: Yongning
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Fujian Environmental Radiation Supervision Station, Fuzhou, Fujian 350012, China.
authors.forename: Minggui
authors.initials: M
authors.lastname: Lin
authors.affiliation: 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.forename: Ye
authors.initials: Y
authors.lastname: He
authors.affiliation: 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.forename: FengFu
authors.initials: F
authors.lastname: Fu
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D002384:Catalysis; D003124:Colorimetry; D021881:DNA, Catalytic / Q000302:isolation & purification*; D060766:Drinking Water / Q000032:analysis; D006046:Gold / Q000737:chemistry; D057230:Limit of Detection; D060526:Magnetic Fields; D053768:Metal Nanoparticles / Q000737:chemistry; D014481:United States; D017974:Uranium Compounds / Q000302:isolation & purification* / Q000633:toxicity
chemical_list: D021881:DNA, Catalytic; D060766:Drinking Water; D017974:Uranium Compounds; C114698:uranium peroxide; D006046:Gold
keywords: AuNPs; Colorimetric biosensor; DNAzyme; Magnetic beads; Uranyl ion