Electrochemical coupled immunosensing platform based on graphene oxide/gold nanocomposite for sensitive detection of Cronobacter sakazakii in powdered infant formula.
Biosens Bioelectron
; 109: 139-149, 2018 Jun 30.
Article
em En
| MEDLINE
| ID: mdl-29550737
ABSTRACT
A sensitive electrochemical immunosensing platform for the detection of Cronobacter sakazakii was developed using a graphene oxide/gold (GO/Au) composite. Transmission electron microscopy showed that the Au nanoparticles, with an average size of <â¯30â¯nm, were well dispersed on the GO surface. For the detection of C. sakazakii, a polyclonal anti-C. sakazakii antibody (IgG) was covalently immobilized to the Au nanoparticles on the surface of the GO/Au composite coated glassy carbon electrode (GCE). The electrochemical sensing performance of immunofunctionalized GCE was characterized by cyclic voltammetry and differential pulse voltammetry. Under optimized conditions, in pure culture there was a linear relationship between electrical signal and C. sakazakii levels over the range 2.0â¯×â¯102-2.0â¯×â¯107 cfu/mL (R2 =â¯0.999), with a detection limit of 2.0â¯×â¯101 cfu/mL. The total analytical time was 15â¯min per sample. The C. sakazakii electrochemical immunosensing assay was able to successfully detect 2.0â¯×â¯101 cfu/mL of C. sakazakii in artificially contaminated powdered infant formula without any enrichment or pre-enrichment steps. Furthermore, the recovery rates of the C. sakazakii electrochemical immunosensing assay following spiking of powdered infant formula with different concentrations of C. sakazakii (cfu/mL) were 82.58% at 2.0â¯×â¯101 cfu/mL, 84.86% at 2.0â¯×â¯102 cfu/mL, and 95.40% at 2.0â¯×â¯103 cfu/mL. The C. sakazakii electrochemical immunosensing assay had good selectivity, reproducibility, and reactivity compared with other Cronobacter spp. and/or pathogens belonging to other genera, indicating its significant potential in the clinical diagnosis of C. sakazakii.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Técnicas Biossensoriais
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Cronobacter sakazakii
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Fórmulas Infantis
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Técnicas Eletroquímicas
Tipo de estudo:
Diagnostic_studies
Limite:
Humans
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Infant
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article