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Phthalocyanine‐Sensitized Graphene–CdS Nanocomposites: An Enhanced Photoelectrochemical Immunosensing Platform
Author(s) -
Li YongJie,
Ma MengJie,
Yin Gui,
Kong Yong,
Zhu JunJie
Publication year - 2013
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201203521
Subject(s) - photocurrent , nanocomposite , graphene , phthalocyanine , materials science , detection limit , nanotechnology , linear range , chemical engineering , chemistry , optoelectronics , chromatography , engineering
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 pg mL −1 to 5 μg mL −1 with a detection limit of 0.63 pg mL −1 . The proposed sensor shows high sensitivity, stability, reproducibility, and can become a promising platform for other biomolecular detection.