title: A highly sensitive disposable immunosensor through direct electro-reduction of oxygen catalyzed by palladium nanoparticle decorated carbon nanotube label.
abstract: A palladium nanoparticle decorated carbon nanotube was designed as a label for preparation of a highly sensitive disposable immunosensor. The immunosensor was constructed by assembling the capture antibody on gold nanoparticles decorated graphene nanosheets modified screen printed carbon working electrode. With a sandwich immunoassay mode, the palladium nanoparticle decorated carbon nanotubes were captured to the immunocomplex and showed strong electrocatalytic activity toward oxygen reduction. The use of carbon nanotube carrier offered a high amount of palladium nanoparticles on each immunoconjugate, hence amplified the detectable signal from the electro-reaction of dissolved oxygen. The graphene nanosheets and gold nanoparticles improved the electronic conductivity and the hydrophilicity of electrode surface for immobilization of the capture antibody, respectively. Under optimal conditions, a linear detection range from 50 pg/mL to 10 ng/mL and a limit of detection of 44 pg/mL (0.3 pM) were achieved for human IgG. Using dissolved oxygen as a signal reporter, the detection process avoided deoxygenation. The immunosensor showed acceptable stability, precision and accuracy, indicating potential applications in clinical diagnostics.
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, Department of Chemistry, Nanjing University, Nanjing, PR China.
authors.forename: Chuan
authors.initials: C
authors.lastname: Leng
authors.forename: Jie
authors.initials: J
authors.lastname: Wu
authors.forename: Qiunan
authors.initials: Q
authors.lastname: Xu
authors.forename: Guosong
authors.initials: G
authors.lastname: Lai
authors.forename: Huangxian
authors.initials: H
authors.lastname: Ju
authors.forename: Feng
authors.initials: F
authors.lastname: Yan
mesh_terms: D000906:Antibodies / Q000737:chemistry; D015374:Biosensing Techniques; D002384:Catalysis; D006046:Gold / Q000737:chemistry; D006108:Graphite / Q000737:chemistry; D006801:Humans; D007118:Immunoassay; D053768:Metal Nanoparticles / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D010165:Palladium / Q000737:chemistry*; D012680:Sensitivity and Specificity
chemical_list: D000906:Antibodies; D037742:Nanotubes, Carbon; D010165:Palladium; D006046:Gold; D006108:Graphite; D010100:Oxygen