Influence of antibody immobilization strategies on the analytical performance of a magneto-elastic immunosensor for Staphylococcus aureus detection.
Mater Sci Eng C Mater Biol Appl
; 76: 1232-1239, 2017 Jul 01.
Article
en En
| MEDLINE
| ID: mdl-28482491
ABSTRACT
Magneto-elastic (ME) sensors have a great advantage in microbiology due to their ability to be queried wirelessly. Staphylococcus aureus is one of the most common bacteria widespread in the environment and a major human pathogen related to numerous illnesses. Immunosensors are affinity-based assays where the analyte is highly selective. The immobilization of antibodies (Ab) is an important step in the development of such devices. This study compared the effects of two antibody immobilization strategies on the analytical performance of a magneto-elastic immunosensor (1) random antibody covalent immobilization (CysAb) and (2) specific-oriented antibody covalent immobilization (PrGAb). Immunosensors were exposed to solutions containing S. aureus at different concentrations (104 to 108CFU/ml) and sensor resonant frequencies were measured. In order to confirm that the frequency shifts were mainly caused by the binding of S. aureus to the sensor's surface, scanning electron microscope (SEM) and indirect immunofluorescence (IIF) images were taken after bacteria exposure at 108CFU/ml. Sensor surfaces were further monitored by non-contact topographic atomic force microscopy (AFM) images. In the covalent-oriented strategy, PrG was first bound covalently to the surface, which in turn, then binds the anti-S. aureus antibody in an oriented manner. Topographic AFM images showed different surface patterns between the two antibody immobilization strategies. Specific-oriented antibody covalent immobilization (PrGAb) strategy gave the highest anti-S. aureus antibody immobilization density. Therefore, the covalent-oriented strategy presented the best performance for S. aureus capture, detecting 104CFU/ml.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Staphylococcus aureus
Tipo de estudio:
Diagnostic_studies
Idioma:
En
Revista:
Mater Sci Eng C Mater Biol Appl
Año:
2017
Tipo del documento:
Article
País de afiliación:
Brasil