title: Carbon nanospheres enhanced electrochemiluminescence of CdS quantum dots for biosensing of hypoxanthine.
abstract: This work developed a novel method to greatly enhance the electrochemiluminescence (ECL) of CdS quantum dots (QDs). The ECL amplification was achieved by the assembly of QDs on poly (diallyldimethylammonium chloride)-functionalized carbon nanospheres (PFCNSs), and successfully employed for sensitive ECL biosensing of oxidase substrates. The carbon nanospheres were prepared by a "green" method, and the high loading of QDs on carbon nanospheres led to a 4-times increased ECL intensity with dissolved O(2) as the coreactant. Using xanthine oxidase (XOD) as a model, an ECL biosensor was fabricated by immobilizing the enzyme on the mixing membrane of PFCNSs and QDs. The ECL biosensor showed a fast response to hypoxanthine with a linear concentration range from 2.5 × 10(-8) to 1.4 × 10(-5)M. The limit of detection was 5 nM at a signal-to-noise ratio of 3. The assay results of hypoxanthine in fish samples were in a good agreement with the reference values by amperometric technique. This facile approach to prepare the PFCNSs/QDs system for ECL biosensing could be of promising application in bioanalysis and electronic device.
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, Department of Chemistry, Nanjing University, Nanjing 210093, PR China.
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Zhang
authors.forename: Shengyuan
authors.initials: S
authors.lastname: Deng
authors.forename: Jianping
authors.initials: J
authors.lastname: Lei
authors.forename: Qiunan
authors.initials: Q
authors.lastname: Xu
authors.forename: Huangxian
authors.initials: H
authors.lastname: Ju
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D019187:Cadmium Compounds / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D058266:Dielectric Spectroscopy; D004563:Electrochemistry; D004566:Electrodes; D005399:Fishes; D005898:Glass / Q000737:chemistry; D019271:Hypoxanthine / Q000032:analysis*; D008163:Luminescent Measurements; D054118:Nanospheres / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D011095:Polyethylenes / Q000737:chemistry; D045663:Quantum Dots; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D013440:Sulfides / Q000737:chemistry*; D014969:Xanthine Oxidase / Q000378:metabolism
chemical_list: D019187:Cadmium Compounds; D011095:Polyethylenes; D000644:Quaternary Ammonium Compounds; D013440:Sulfides; C034939:cadmium sulfide; C041004:poly-N,N-dimethyl-N,N-diallylammonium chloride; D019271:Hypoxanthine; D002244:Carbon; D014969:Xanthine Oxidase; D010100:Oxygen