title: In situ enzymatic ascorbic acid production as electron donor for CdS quantum dots equipped TiO2 nanotubes: a general and efficient approach for new photoelectrochemical immunoassay.
abstract: In this work, a novel photoelectrochemical (PEC) immunoanalysis format was developed for sensitive and specific detection of prostate-specific antigen (PSA) based on an in situ electron donor producing approach. Thioglycolic acid-capped CdS quantum dots (QDs) equipped TiO(2) nanotubes (NTs) were fabricated via a facile electrostatic adsorption method. The coupling of CdS QDs and TiO(2) NTs results in an enhanced excitation and photo-to-electric conversion efficiency. Using alkaline phosphatase catalytic chemistry to in situ generate ascorbic acid for electron donating, an exquisite immunosandwich protocol was successfully constructed for the PSA assay due to the dependence of the photocurrent signal on the concentration of electron donor. This work opens a different perspective for transducer design in PEC detection and provides a general format for future development of PEC immunoanalysis.
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Wei-Wei
authors.initials: WW
authors.lastname: Zhao
authors.forename: Zheng-Yuan
authors.initials: ZY
authors.lastname: Ma
authors.forename: Dong-Yang
authors.initials: DY
authors.lastname: Yan
authors.forename: Jing-Juan
authors.initials: JJ
authors.lastname: Xu
authors.forename: Hong-Yuan
authors.initials: HY
authors.lastname: Chen
mesh_terms: D001205:Ascorbic Acid / Q000138:chemical synthesis*; D015374:Biosensing Techniques / Q000379:methods; D019187:Cadmium Compounds / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000379:methods*; D043942:Nanotubes / Q000737:chemistry*; D055668:Photochemical Processes; D045663:Quantum Dots / Q000737:chemistry*; D013431:Sulfates / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
chemical_list: D019187:Cadmium Compounds; D013431:Sulfates; C009495:titanium dioxide; C037123:cadmium sulfate; D014025:Titanium; D001205:Ascorbic Acid