title: Construction of dentate bonded TiO2-CdSe heterostructures with enhanced photoelectrochemical properties: versatile labels toward photoelectrochemical and electrochemical sensing.
abstract: A facile synthetic route for TiO2-CdSe heterostructures was proposed based on dentate binding of TiO2 to carboxyl. Carboxyl functionalized CdSe quantum dots (CF-CdSe QDs) were successfully bonded onto TiO2 nanoparticles (NPs), which could significantly improve the photoelectrochemical (PEC) properties of TiO2 NPs. This is ascribed to the fact that CdSe QDs with a narrow band gap could be stimulated under visible light irradiation, and the energy levels of TiO2 NPs and CF-CdSe QDs are aligned with an electrolyte solution. High resolution transmission electron microscopy images revealed the heterostructures of the TiO2-CdSe composites. Ultraviolet visible spectroscopy, photoluminescence emission spectroscopy and electrochemical impedance spectroscopy analysis exhibited that the prepared TiO2-CdSe heterostructures have improved light absorption, charge separation efficiency and electron transfer ability in the visible light region. TiO2-CdSe heterostructures were used as versatile labels for fabrication of PEC and electrochemical immunosensors, and human immune globulin G (HIgG) was used as a model analyte. The immunosensor showed high sensitivity, a low detection limit and a wide linear range, which could be applied in practical serum sample analysis. The constructed TiO2-CdSe heterostructures would have potential applications in photocatalysis, aptasensors, cytosensors and other areas of nanotechnology.
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China. sdjndxwq@163.com.
authors.forename: Picheng
authors.initials: P
authors.lastname: Gao
authors.forename: Hongmin
authors.initials: H
authors.lastname: Ma
authors.forename: Tao
authors.initials: T
authors.lastname: Yan
authors.forename: Dan
authors.initials: D
authors.lastname: Wu
authors.forename: Xiang
authors.initials: X
authors.lastname: Ren
authors.forename: Jiaojiao
authors.initials: J
authors.lastname: Yang
authors.forename: Bin
authors.initials: B
authors.lastname: Du
authors.forename: Qin
authors.initials: Q
authors.lastname: Wei
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000379:methods*; D015394:Molecular Structure; D055668:Photochemical Processes; D045663:Quantum Dots; D018036:Selenium Compounds / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
chemical_list: D019187:Cadmium Compounds; D018036:Selenium Compounds; C009495:titanium dioxide; C058667:cadmium selenide; D014025:Titanium