title: In-situ assembly of biocompatible core-shell hierarchical nanostructures sensitized immunosensor for microcystin-LR detection.
abstract: Microcystin-LR (MC-LR) is a kind of hepatotoxin which can cause functional and structural disturbances of the liver, accumulate in aquatic organisms and transfer to higher trophic levels, a biocompatible electrochemical immunosensor was constructed to detect MC-LR sensitively and selectively. The three-dimensional villiform-like carbon nanotube/cobalt silicate (CNT@Co silicate) core-shell nanocomposites were synthesized and firstly used as the substrate to immobilize the antigen of MC-LR (Ag), while Fe3O4 nanoclusters/polydopamine/gold nanoparticles (Fe3O4@PDA-Au) core-shell magnetic nanocomposites were prepared as the label carrier of the immunosensor to conjugate the second antibody (Ab2) and horse radish peroxidase (HRP). Since the toxicity of nanomaterials is important in the construction of biosensors including the immobilization of antigen or antibody, the biocompatibility of such nanocomposites were investigated by monitoring the cell viability after culturing with Hela cells. Due to the excellent biocompatibility, the immunosensor can immobilize more antigens by the large surface area of the three-dimensional villiform-like structure in CNT@Co silicate, and provide high electrochemical signals by Fe3O4@PDA-Au labeled Ab2 and HRP. After investigation of the binding capability of biomolecules on nanomaterials and optimization of the conditions in the competitive immunoassay, the proposed electrochemical immunosensor shows a linear response to MC-LR in the range from 0.005 μg/L to 50 μg/L with a detection limit of 0.004 μg/L. In addition, the specificity, reproducibility and stability of the immunosensor were also proved to be acceptable, indicating its potential application in environmental monitoring.
authors.affiliation: Institute of Biomaterials, College of Materials & Energy, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Cuifen
authors.initials: C
authors.lastname: Gan
authors.affiliation: The Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Li
authors.initials: L
authors.lastname: Ling
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: The Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Hongtao
authors.initials: H
authors.lastname: Lei
authors.affiliation: Institute of Biomaterials, College of Materials & Energy, South China Agricultural University, Guangzhou 510642, China. Electronic address: liuyingju@hotmail.com.
authors.forename: Yingju
authors.initials: Y
authors.lastname: Liu
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry; D015374:Biosensing Techniques; D055664:Electrochemical Techniques; D006046:Gold / Q000737:chemistry; D006801:Humans; D007118:Immunoassay; D007211:Indoles / Q000737:chemistry; D057230:Limit of Detection; D008387:Marine Toxins; D052998:Microcystins / Q000302:isolation & purification*; D049329:Nanostructures / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry
chemical_list: D055910:Antibodies, Immobilized; D007211:Indoles; D008387:Marine Toxins; D052998:Microcystins; D037742:Nanotubes, Carbon; D011108:Polymers; C568283:polydopamine; D006046:Gold; C057862:cyanoginosin LR
keywords: Carbon nanotube/cobalt silicate (CNT@Co silicate); Electrochemical immunosensor; Fe(3)O(4)@polydopamine–gold nanocomposite; Microcystin-LR