title: Reusable DNA-functionalized-graphene for ultrasensitive mercury (II) detection and removal.
abstract: Mercury is a bioaccumulative and highly toxic heavy metal. Thus, the removal and detection of Hg2+from the environment is a major challenge. This paper reports a novel bio-nanomaterial for the simultaneous determination and removal of Hg2+with the use of rGO-Fe3O4functionalized with Hg2+-specific thymine oligonucleotide (T-DNA). T-DNA interacts with Hg2+and changes from having a random coil into a hairpin structure, thereby increasing the fluorescence of SYBR Green I. Such fluorescence turn-on process allows the detection of Hg2+in the concentration range of 1-20ng/mL, with a detection limit of 0.82ng/mL. Removal is achieved by exploiting the T-Hg2+-T base pairs and the large surface area of graphene; these bio-nanocomposites exhibit excellent removal efficiency (over 80%) and rapid separation from the aqueous solution. Moreover, bio-nanomaterials can be regenerated after a simple treatment. The proposed method also demonstrates the evident practicability of the simultaneous detection and removal of Hg2+in lake water samples.
authors.affiliation: State Key Joint Laboratory of Environmental Simulate & Pollution Control, School of Environment, Tsinghua University, Beijing 10084, China. Electronic address: liuyc@tsinghua.edu.cn.
authors.forename: Yanchen
authors.initials: Y
authors.lastname: Liu
authors.affiliation: State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Xiangqing
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Wu
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D052160:Benzothiazoles; D015374:Biosensing Techniques / Q000379:methods*; D003959:Diamines; D004784:Environmental Monitoring / Q000379:methods; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D061925:Immobilized Nucleic Acids / Q000737:chemistry; D060106:Lakes / Q000032:analysis; D057230:Limit of Detection; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D008628:Mercury / Q000032:analysis* / Q000302:isolation & purification; D009930:Organic Chemicals / Q000737:chemistry; D011804:Quinolines; D013941:Thymine / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000302:isolation & purification; D018508:Water Purification / Q000379:methods*
chemical_list: D052157:Aptamers, Nucleotide; D052160:Benzothiazoles; D003959:Diamines; D005456:Fluorescent Dyes; D061925:Immobilized Nucleic Acids; D058185:Magnetite Nanoparticles; D009930:Organic Chemicals; D011804:Quinolines; D014874:Water Pollutants, Chemical; C098022:SYBR Green I; D006108:Graphite; D008628:Mercury; D013941:Thymine
keywords: Aptamers; Detection; Graphene; Mercury; Removal