title: Optimized ferrocene-functionalized ZnO nanorods for signal amplification in electrochemical immunoassay of Escherichia coli.
abstract: A novel amplified electrochemical immunoassay based on ferrocene (Fc)-functionalized ZnO nanorods (NRs) was developed in the present work. The detection antibody ((d)Ab) and Fc were immobilized onto the surface of ZnO NRs, denoted as {(d)Ab-ZnO-Fc} bioconjugates. The amount of (d)Ab and Fc in the bioconjugates was investigated using the copper reduction/bicinchoninic acid reaction (BCA protein assay) and inductive coupled plasma-atomic emission spectroscopy (ICP-AES), respectively. Greatly amplified signal was achieved in the sandwich-type immunoassay when (d)Ab and Fc linked to ZnO NRs at a proper ratio. Using Escherichia coli (E. coli) as a model antigen, the designed immunoassay showed an excellent analytical performance, and exhibited a wide dynamic response range of E. coli concentration from 10(2) to 10(6)cfu/mL with a detection limit of 50 cfu/mL (S/N=3). By introducing a pre-enrichment step, the detection of 5 cfu/10 mL E. coli in hospital sewage water was realized. This proposed signal amplification strategy was promising and could be easily extended to monitor other biorecognition events.
authors: Department of Chemistry, East China Normal University, 3663th Zhongshan Rd. (N), Shanghai 200062, PR China.
authors: Yingqiao
authors: Y
authors: Teng
authors: Xinai
authors: X
authors: Zhang
authors: Ying
authors: Y
authors: Fu
authors: Huijie
authors: H
authors: Liu
authors: Zhongchuan
authors: Z
authors: Wang
authors: Litong
authors: L
authors: Jin
authors: Wen
authors: W
authors: Zhang
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry* / Q000276:immunology; D015374:Biosensing Techniques / Q000379:methods; D055664:Electrochemical Techniques / Q000379:methods*; D004926:Escherichia coli / Q000276:immunology / Q000302:isolation & purification*; D005296:Ferrous Compounds / Q000737:chemistry*; D007118:Immunoassay / Q000379:methods; D057230:Limit of Detection; D000075163:Metallocenes; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D015034:Zinc Oxide / Q000737:chemistry
chemical_list: D055910:Antibodies, Immobilized; D005296:Ferrous Compounds; D000075163:Metallocenes; D015034:Zinc Oxide; C004998:ferrocene