title: N-doped TiO2 based visible light activated label-free photoelectrochemical biosensor for detection of Hg(2+) through quenching of photogenerated electrons.
abstract: A novel photoelectrochemical (PEC) biosensor was fabricated based on N-doped TiO2 for the detection of Hg(2+) through the quenching of photogenerated electrons. The N-doped TiO2 was synthesized by a sol-gel method with urea and tetrabutyl titanate as the N and Ti sources. Compared with the undoped TiO2, the N-doped TiO2 showed an enhanced photocurrent response under visible light (λ > 420 nm). The sensing surface was functionalized with 5'-amino-modified T-rich oligonucleotides. The photoelectrochemical biosensor bound Hg(2+) on the surface by a highly specific T-Hg(2+)-T recognition. Hg(2+) on the surface of the N-doped TiO2 film withdrew the photogenerated electrons and decreased the recorded current signal. The dynamic linear range for Hg(2+) has been determined to be as low as 2-6 μM.
authors.affiliation: Key Laboratory of Nano-Bio Interface, Division of Nanobiomedicine, Collaborative Innovation Center of Suzhou Nano Science and Technology, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215123, China. rjpei2011@sinano.ac.cn.
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Han
authors.forename: Kewei
authors.initials: K
authors.lastname: Wang
authors.forename: Lijun
authors.initials: L
authors.lastname: Xu
authors.forename: Xiang
authors.initials: X
authors.lastname: Yan
authors.forename: Kunchi
authors.initials: K
authors.lastname: Zhang
authors.forename: Xing
authors.initials: X
authors.lastname: Chen
authors.forename: Qinglin
authors.initials: Q
authors.lastname: Wang
authors.forename: Lan
authors.initials: L
authors.lastname: Zhang
authors.forename: Renjun
authors.initials: R
authors.lastname: Pei
mesh_terms: D000327:Adsorption; D015374:Biosensing Techniques / Q000379:methods*; D002384:Catalysis; D004563:Electrochemistry; D004579:Electron Transport; D005976:Glutaral / Q000737:chemistry; D006900:Hydroxylation; D008027:Light; D057230:Limit of Detection; D008628:Mercury / Q000032:analysis* / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry*; D055668:Photochemical Processes; D011437:Propylamines / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D014025:Titanium / Q000737:chemistry*
chemical_list: D011437:Propylamines; D012821:Silanes; C009495:titanium dioxide; D014025:Titanium; D008628:Mercury; C477625:amino-propyl-triethoxysilane; D009584:Nitrogen; D005976:Glutaral