A dual-signal readout enzyme-free immunosensor based on hybridization chain reaction-assisted formation of copper nanoparticles for the detection of microcystin-LR.
Biosens Bioelectron
; 126: 151-159, 2019 Feb 01.
Article
en En
| MEDLINE
| ID: mdl-30399517
ABSTRACT
Enzyme-based electrochemical biosensors are widely used in immunoassays, but the intrinsic disadvantages of enzymes including instability or sensitivity to temperature and pH should be considered. Herein, an enzyme-free and dual-signal readout immunoassay was established to detect microcystin-LR (MC-LR) sensitively and selectively. Firstly, the microplate was modified with gold nanoparticles-decorated-carbon nanotubes (AuNP-CNT) to immobilize sufficient antigens by the high surface area of CNT and high affinity of AuNP. Then, silver nanoparticles were decorated on gold nanorods to form corn-like AgNP/AuNR composite and then capture secondary antibody and initiator DNA strand. After hybridization chain reaction, long double helix DNA strands can be formed on AgNP/AuNR to germinate copper nanoparticles. A dual-signal readout from the current responses of both silver and copper ions was obtained by using differential pulse stripping voltammetry with the aid of acid-treatment. By using a competitive immunoreaction, MC-LR can be detected in a linear range from 0.005⯵g/L to 20⯵g/L with a lower detection limit of 2.8â¯ng/L. The reproducibility, stability and specificity were all acceptable, indicating its promising application in environment monitoring and sensitive electrochemical detection for other analytes.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Técnicas Biosensibles
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Cobre
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Microcistinas
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Nanopartículas del Metal
Tipo de estudio:
Diagnostic_studies
Idioma:
En
Revista:
Biosens Bioelectron
Asunto de la revista:
BIOTECNOLOGIA
Año:
2019
Tipo del documento:
Article
País de afiliación:
China