title: Electrochemical immunosensor of tumor necrosis factor α based on alkaline phosphatase functionalized nanospheres.
abstract: A novel immunosensor for sensitive detection of tumor necrosis factor α was reported. First of all, gold nanoparticles were uniformly assembled on the surface of poly (styrene-acrylic acid) nanospheres, which was used as the matrix to conjugate alkaline phosphatase (ALP). And then, the obtained composite was used as multi-enzyme functionalized label for immunoassay. Biocompatible polyaniline doped with poly (acrylic acid) was electro-polymerized at the glass carbon electrode to construct the matrix for the immobilization of antibody TNF-α. After the sandwich immunoreaction, the labeled ALP was used to hydrolyze α-naphthyl phosphate to produce the electroactive α-naphthol, which could be amperometrically detected. The results showed that the electrochemical signals were proportional to the logarithm of the antigen concentration in the range of 0.02-200.00 ng/mL with the detection limit of 0.01 ng/mL. The developed immunoassay showed high sensitivity, acceptable stability and reproducibility, which might have potentially broad applications in protein diagnostics and bioassay.
authors.affiliation: Key Lab of Analytical Chemistry for Life Science (MOE), School of Chemistry and Chemical Engineering, Nanjing University, Hankou Road 22, Nanjing 210093, PR China.
authors.forename: Zhengzhi
authors.initials: Z
authors.lastname: Yin
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Jiang
authors.forename: Jun-Jie
authors.initials: JJ
authors.lastname: Zhu
mesh_terms: D000469:Alkaline Phosphatase / Q000737:chemistry* / Q000276:immunology; D015374:Biosensing Techniques / Q000295:instrumentation*; D003217:Conductometry / Q000295:instrumentation*; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000276:immunology; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007118:Immunoassay / Q000295:instrumentation*; D054118:Nanospheres / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000295:instrumentation*; D010316:Particle Size; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis* / Q000737:chemistry / Q000276:immunology
chemical_list: D004800:Enzymes, Immobilized; D014409:Tumor Necrosis Factor-alpha; D000469:Alkaline Phosphatase