title: A multi-walled carbon nanotubes-poly(L-lysine) modified enantioselective immunosensor for ofloxacin by using multi-enzyme-labeled gold nanoflower as signal enhancer.
abstract: The enantioselective detection of trace amounts of ofloxacin is very important in many fields. In this work, an enantioselective and sensitive electrochemical immunosensor was constructed for the detection of chiral antibiotic ofloxacin based on a dual amplification strategy using multiwall carbon nanotubes-poly(L-lysine) as a matrix to immobilize the antigen and multi-enzyme-antibody functionalized gold nanoflowers as an electrochemical detection label. The fabrication process of the dual-amplified immunosensor was characterized by scanning electron microscopy, cyclic voltammogram and electrochemical impedance spectroscopy, respectively. After the optimization of the experimental conditions, a competitive immunoassay, i.e., the association ability with the corresponding antibody between the captured antigen and free S-OFL or R-OFL in the solution, showed that the immunosensor exhibited a sensitive response to S-OFL in the range from 0.26 to 25.6 ng/mL with a detection limit of 0.15 ng/mL as well as a sensitive response to R-OFL in the range from 0.37 to 12.8 ng/mL with a detection limit of 0.30 ng/mL. Along with the acceptable sensitivity and stability, the S-OFL or R-OFL immunosensor showed selective ability to its corresponding enantiomer, suggesting this amplification strategy may hold a potential application in the detection of OFL in food or environment.
authors.affiliation: Institute of Biomaterials, College of Materials & Energy, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Zuyu
authors.initials: Z
authors.lastname: He
authors.affiliation: Institute of Biomaterials, College of Materials & Energy, South China Agricultural University, Guangzhou 510642, China; The Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Zang
authors.affiliation: Institute of Biomaterials, College of Materials & Energy, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Yingju
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Institute of Biomaterials, College of Materials & Energy, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: He
authors.affiliation: The Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Hongtao
authors.initials: H
authors.lastname: Lei
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis / Q000737:chemistry / Q000276:immunology; D000918:Antibody Specificity; D015374:Biosensing Techniques / Q000379:methods*; D004785:Environmental Pollutants / Q000032:analysis; D005506:Food Contamination / Q000032:analysis; D006046:Gold; D006735:Horseradish Peroxidase; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D053768:Metal Nanoparticles / Q000648:ultrastructure; D037742:Nanotubes, Carbon / Q000648:ultrastructure; D015242:Ofloxacin / Q000032:analysis* / Q000737:chemistry / Q000276:immunology; D011107:Polylysine; D013237:Stereoisomerism
chemical_list: D000900:Anti-Bacterial Agents; D004785:Environmental Pollutants; D037742:Nanotubes, Carbon; D011107:Polylysine; D006046:Gold; D015242:Ofloxacin; D006735:Horseradish Peroxidase
keywords: Enantioselective; Gold nanoflowers; Immunosensor; Ofloxacin