Ultrasensitive sandwich-type photoelectrochemical immunosensor based on CdSe sensitized La-TiO2matrix and signal amplification of polystyrene@Ab2composites.
A novel and sensitive sandwich-type photoelectrochemical (PEC) sensor was fabricated using signal amplification strategy for the quantitative detection of the prostate specific antigen (PSA). CdSe nanoparticles (NPs) sensitized lanthanum-doped titanium dioxide (La-TiO2) composites were used to bind the primary antibodies (Ab1). The doping of lanthanum promoted the visible light absorption of TiO2and remarkably enhanced the photocurrent. Moreover, 0.3%La-TiO2displayed the highest photocurrent in the La-TiO2composites, which was twice as much as that of undoped TiO2. Carboxyl modified CdSe NPs were assembled onto La-TiO2composites via the dentate binding between -COOH and Ti atom in TiO2NPs, which dramatically promoted the photocurrent intensity by approximately 2.1 times. Carboxyl functionalized polystyrene (PS) microspheres were coated with the secondary antibodies (Ab2). Owing to the better insulation property and steric hindrance of the prepared polystyrene@Ab2(PS@Ab2) composites, the significant reduction of the photocurrent signal was achieved after the specific immune recognition. Under the optimum experimental conditions, the fabricated PEC sensor realized ultrasensitive detection of PSA in the range of 0.05-100pgmL-1with a detection limit of 17fgmL-1. Moreover, this well-designed PEC immunoassay exhibited ideal reproducibility, stability, and selectivity, which is a promising platform for the detection of other important tumor targets.
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022 China.
Dawei
D
Fan
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022 China.
Xiang
X
Ren
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022 China.
Haoyuan
H
Wang
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022 China.
Dan
D
Wu
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022 China.
Di
D
Zhao
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022 China.
Yucheng
Y
Chen
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022 China. Electronic address: sdjndxwq@163.com.
Qin
Q
Wei
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022 China.
Bin
B
Du
D055910:Antibodies, Immobilized / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods; D019187:Cadmium Compounds / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000379:methods; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D018796:Immunoconjugates / Q000737:chemistry*; D007811:Lanthanum / Q000737:chemistry*; D008027:Light; D057230:Limit of Detection; D053758:Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D055668:Photochemical Processes; D011137:Polystyrenes / Q000737:chemistry*; D017430:Prostate-Specific Antigen / Q000097:blood*; D018036:Selenium Compounds / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
D055910:Antibodies, Immobilized; D019187:Cadmium Compounds; D018796:Immunoconjugates; D011137:Polystyrenes; D018036:Selenium Compounds; C009495:titanium dioxide; D007811:Lanthanum; C058667:cadmium selenide; D014025:Titanium; D017430:Prostate-Specific Antigen
CdSe; La-TiO(2); Polystyrene; Prostate specific antigen; Sandwich-type photoelectrochemical sensor