Carbon nanohorn sensitized electrochemical immunosensor for rapid detection of microcystin-LR.
A sensitive electrochemical immunosensor was proposed by functionalizing single-walled carbon nanohorns (SWNHs) with analyte for microcystin-LR (MC-LR) detection. The functionalization of SWNHs was performed by covalently binding MC-LR to the abundant carboxylic groups on the cone-shaped tips of SWNHs in the presence of linkage reagents and characterized with Raman spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and a transmission electron micrograph. Compared with single-walled carbon nanotubes, SWNHs as immobilization matrixes showed a better sensitizing effect. Using home-prepared horseradish peroxidase-labeled MC-LR antibody for the competitive immunoassay, under optimal conditions, the immunosensor exhibited a wide linear response to MC-LR ranging from 0.05 to 20 microg/L with a detection limit of 0.03 microg/L at a signal-to-noise of 3. This method showed good accuracy, acceptable precision, and reproducibility. The assay results of MC-LR in polluted water were in a good agreement with the reference values. The proposed strategy provided a biocompatible immobilization and sensitized recognition platform for analytes as small antigens and possessed promising application in food and environmental monitoring.
Zhang
Jing
J
Key Laboratory of Analytical Chemistry for Life Science (Ministry of Education of China), Department of Chemistry, Nanjing University, Nanjing 210093, P. R. China.
Lei
Jianping
J
Xu
Chuanlai
C
Ding
Lin
L
Ju
Huangxian
H
D055910:Antibodies, Immobilized / Q000276:immunology / Q000378:metabolism; D015374:Biosensing Techniques / Q000379:methods*; D055664:Electrochemical Techniques / Q000379:methods*; D008387:Marine Toxins; D052998:Microcystins / Q000032:analysis*; D037742:Nanotubes, Carbon / Q000737:chemistry*
D055910:Antibodies, Immobilized; D008387:Marine Toxins; D052998:Microcystins; D037742:Nanotubes, Carbon; C057862:cyanoginosin LR