title: Sensitive immunosensor for benzo[a]pyrene detection based on dual amplification strategy of PAMAM dendrimer and amino-modified methylene blue/SiO₂ core-shell nanoparticles.
abstract: A novel electrochemical immunosensor for sensitive detection of benzo[a]pyrene (BaP) is constructed using poly(amido amine) (PAMAM) dendrimer and functionalized methylene blue/SiO2 core-shell nanoparticle (MB/SiO2) loaded with horseradish peroxidase (HRP) and HRP-secondary antibody (HRP-Ab2). Greatly enhanced sensitivity for BaP analysis is based on a dual signal amplification strategy. Firstly, the gold electrode (GE) was amino-functioned by electropolymerization of a novel compound, 2-amino-5,2':5'2''-terthiophene, followed by the modification of G 2.0 PAMAM dendrimer to amplify functional groups on the substrate and thus enhance the immobilization capacity of BaP antigen (BaP-Ag). Secondly, amino-functionalized MB/SiO2 was used to load HRP and HRP-Ab2, and the resulting nanostructure (HRP-MB/SiO2-Ab2) was applied as the detection label for the immunosensor. The proposed immunosensor exhibited a relatively wide linear response between 0.01 and 2.0 ng/mL with a detection limit of 6 pg/mL. This amplification strategy shows excellent promise for environmental monitoring of some pollutants and a potential application in the immunosensor.
authors.affiliation: Institute of Biomaterials, Department of Applied Chemistry, College of Sciences, South China Agricultural University, Wushan, Tianhe, Guangzhou 510642, Guangdong Province, China.
authors.forename: Mouhong
authors.initials: M
authors.lastname: Lin
authors.affiliation: Institute of Biomaterials, Department of Applied Chemistry, College of Sciences, South China Agricultural University, Wushan, Tianhe, Guangzhou 510642, Guangdong Province, China.
authors.forename: Yingju
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Instrumental Analysis & Research Center, South China Agricultural University, Guangzhou 510642, Guangdong Province, China.
authors.forename: Chuanhe
authors.initials: C
authors.lastname: Liu
authors.affiliation: Institute of Biomaterials, Department of Applied Chemistry, College of Sciences, South China Agricultural University, Wushan, Tianhe, Guangzhou 510642, Guangdong Province, China.
authors.forename: Zhuohong
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Institute of Biomaterials, Department of Applied Chemistry, College of Sciences, South China Agricultural University, Wushan, Tianhe, Guangzhou 510642, Guangdong Province, China.
authors.forename: Yibin
authors.initials: Y
authors.lastname: Huang
mesh_terms: D001580:Benzopyrenes / Q000737:chemistry / Q000302:isolation & purification*; D015374:Biosensing Techniques; D050091:Dendrimers / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D006735:Horseradish Peroxidase / Q000737:chemistry; D007118:Immunoassay / Q000379:methods*; D008751:Methylene Blue / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry
chemical_list: D001580:Benzopyrenes; D050091:Dendrimers; C104700:PAMAM Starburst; D006046:Gold; D012822:Silicon Dioxide; D006735:Horseradish Peroxidase; D008751:Methylene Blue