title: Highly sensitive impedimetric immunosensor based on single-walled carbon nanohorns as labels and bienzyme biocatalyzed precipitation as enhancer for cancer biomarker detection.
abstract: A novel sandwich-type electrochemical immunosensor based on functionalized nanomaterial labels and bienzyme (horseradish peroxidase and glucose oxidase) biocatalyzed precipitation was developed for the detection of α-fetoprotein (AFP). The enzymes linked to functionalized nanomaterials as biocatalysts could accelerate the oxidation of 4-chloro-1-naphthol (4-CN) by H2O2 to yield the insoluble product on the electrode surface; the mass loading of the precipitates on the device led to a significant enhanced signal. Cyclic voltammetry and electrochemical impedance spectroscopy techniques were used to monitor the enhanced precipitation of 4-CN that accumulated on the electrode surface and subsequent decrement in the electrode surface area by monitoring the reduction process of the Fe(CN)6(4-/3-) redox couple. Under optimal conditions, the proposed immunosensor showed a high sensitivity and a wide linear range from 0.001 to 60 ng mL(-1) with a low detection limit of 0.33 pg mL(-1). Moreover, the immunosensor exhibited good selectivity, acceptable stability and reproducibility. The amplification strategy showed good promise for clinical screening of tumor biomarkers.
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, People's Republic of China.
authors.forename: Fan
authors.initials: F
authors.lastname: Yang
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: Han
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, People's Republic of China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhuo
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, People's Republic of China.
authors.forename: Zhehan
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, People's Republic of China. Electronic address: yaqinchai@swu.edu.cn.
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Chai
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, People's Republic of China. Electronic address: yuanruo@swu.edu.cn.
authors.forename: Ruo
authors.initials: R
authors.lastname: Yuan
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D015374:Biosensing Techniques / Q000295:instrumentation; D002384:Catalysis; D058266:Dielectric Spectroscopy / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005590:Fractional Precipitation / Q000295:instrumentation; D005949:Glucose Oxidase / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry*; D007118:Immunoassay / Q000295:instrumentation*; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013194:Staining and Labeling; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: D014408:Biomarkers, Tumor; D037742:Nanotubes, Carbon; D000509:alpha-Fetoproteins; D005949:Glucose Oxidase; D006735:Horseradish Peroxidase
keywords: Bienzyme; Enzymatic biocatalytic precipitation; Immunosensor; Single-walled carbon nanohorns; α-fetoprotein (AFP)