title: Quantum dots sensitized titanium dioxide decorated reduced graphene oxide for visible light excited photoelectrochemical biosensing at a low potential.
abstract: A low potential and competitive photoelectrochemical biosensing platform was developed using quantum dots sensitized titanium dioxide decorated reduced graphene oxide (TiO2-RGO) nanocomposites. The nanocomposites were prepared through electrostatic interaction between mercaptoacetic acid wrapped CdSe quantum dots with negative charge and TiO2-RGO hybrids with positive charge obtained via ultrasonic and acid treatments. Electron microscopes and spectroscopes were used to characterize the functionalized nanocomposites films of CdSe/TiO2-RGO, and the fabrication process of the photoelectrochemical biosensor. Based on the high photovoltaic conversion efficiency of CdSe/TiO2-RGO nanocomposites films, after introducing biological recognition and competitive immunoreaction, a low potential and competitive photoelectrochemical biosensor for carcinoembryonic antigen (CEA) detection was fabricated. The synergic effect of horseradish peroxide and benzo-4-chlorohexadienone decreased the background signal, leading to signal amplification. Under the light irradiation of 430 nm and the applied potential of 0 V, the biosensor detected CEA with a linear range from 0.003 to 100 ng mL(-1) and the detection limit was estimated to be 1.38 pg mL(-1) at a S/N of 3. It was satisfactory for clinical sample detection. The proposed competitive and low potential photoelectrochemical biosensor under irradiation of visible light exhibited good performance, which has a promising prospect in clinical diagnose.
authors.affiliation: Jiangsu Collaborative Innovation Center of Biomedical Functional Materials and Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, PR China.
authors.forename: Xianxiang
authors.initials: X
authors.lastname: Zeng
authors.affiliation: Jiangsu Collaborative Innovation Center of Biomedical Functional Materials and Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, PR China.
authors.forename: Jianchun
authors.initials: J
authors.lastname: Bao
authors.affiliation: Jiangsu Collaborative Innovation Center of Biomedical Functional Materials and Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, PR China.
authors.forename: Min
authors.initials: M
authors.lastname: Han
authors.affiliation: Jiangsu Collaborative Innovation Center of Biomedical Functional Materials and Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, PR China.
authors.forename: Wenwen
authors.initials: W
authors.lastname: Tu
authors.affiliation: Jiangsu Collaborative Innovation Center of Biomedical Functional Materials and Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, PR China. Electronic address: daizhihuii@njnu.edu.cn.
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Dai
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D002272:Carcinoembryonic Antigen / Q000032:analysis / Q000097:blood*; D055664:Electrochemical Techniques / Q000379:methods; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D008027:Light; D057230:Limit of Detection; D010084:Oxidation-Reduction; D055668:Photochemical Processes; D045663:Quantum Dots / Q000737:chemistry* / Q000648:ultrastructure; D014025:Titanium / Q000737:chemistry*
chemical_list: D002272:Carcinoembryonic Antigen; C009495:titanium dioxide; D006108:Graphite; D014025:Titanium
keywords: Biosensing; Photoelectrochemistry; Quantum dots; Reduced graphene oxide; Signal amplification