title: Phthalocyanine-sensitized graphene-CdS nanocomposites: an enhanced photoelectrochemical immunosensing platform.
abstract: A novel strategy is developed for the fabrication of graphene-CdS (G-CdS) nanocomposites by in situ growth of CdS nanoparticles onto simultaneously reduced graphite oxide, which is noncovalently functionalized by sodium 1-pyrene sulfonate through strong π-π stacking interactions. Subsequently, cobalt 2,9,16,23-tetraaminophthalocyanine (CoTAPc) is self-assembled on the G-CdS nanocomposites through electrostatic interactions to produce phthalocyanine-sensitized G-CdS nanocomposites. The photoactive superstructure enhances the photocurrent generation capability, and presents an efficient photoelectrochemical immunosensing platform for the ultrasensitive detection of the prostate-specific antigen (PSA). The quantitative measurement of PSA is based on the decrease in the photocurrent intensity of the phthalocyanine-sensitized G-CdS nanocomposites, which results from an increase in the steric hindrance due to the formation of the immunocomplex. A linear relationship between the photocurrent decrease and the PSA concentration is obtained in the wide range from 1 pgmL(-1) to 5 μgmL(-1) with a detection limit of 0.63 pgmL(-1). The proposed sensor shows high sensitivity, stability, reproducibility, and can become a promising platform for other biomolecular detection.
authors: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China.
authors: Yong-Jie
authors: YJ
authors: Li
authors: Meng-Jie
authors: MJ
authors: Ma
authors: Gui
authors: G
authors: Yin
authors: Yong
authors: Y
authors: Kong
authors: Jun-Jie
authors: JJ
authors: Zhu
mesh_terms: D015374:Biosensing Techniques / Q000379:methods; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D007211:Indoles / Q000737:chemistry*; D054833:Isoindoles; D057230:Limit of Detection; D008297:Male; D053761:Nanocomposites / Q000737:chemistry*; D055668:Photochemical Processes; D017430:Prostate-Specific Antigen / Q000032:analysis; D015203:Reproducibility of Results
chemical_list: D007211:Indoles; D054833:Isoindoles; D006108:Graphite; D017430:Prostate-Specific Antigen; C013647:phthalocyanine