Surface plasmon resonance immunosensor for bacteria detection

• Published in: Talanta (Oxford) Vol. 82; no. 2; pp. 810 - 814
• Main Authors: Baccar, H., Mejri, M.B., Hafaiedh, I., Ktari, T., Aouni, M., Abdelghani, A.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15-07-2010; Elsevier
• Subjects: Analytical chemistry; Bacteria - chemistry; Bacteria - classification; Bacteria - cytology; Biofunctionalization; Biological and medical sciences; Biosensing Techniques; Biosensors; Biotechnology; Chemistry; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General, instrumentation; Gold - chemistry; Gold nanoparticles; Immunosensor; Immunosorbent Techniques - instrumentation; Limit of Detection; Methods. Procedures. Technologies; Nanoparticles - chemistry; Optics and Photonics - instrumentation; Optics and Photonics - methods; SPR; Surface Plasmon Resonance - methods; Surface Properties; Various methods and equipments; SPR; Biofunctionalization; Gold nanoparticles; Immunosensor; Self-assembled layer; Monolayer; Nanoparticle; Escherichia coli; Immobilization; Modeling; Chemical enrichment; Detection limit; Bacteria; Enterobacteriaceae; Gold; Thiol; Multilayer; Antibody; Chemical sensor; Substrate; Adsorption; Reproducibility; Biosensor; Software; Surface plasmon resonance; Technique; Detection
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2010.05.060

This work describes an approach for the development of two bacteria biosensors based on surface plasmon resonance (SPR) technique. The first biosensor was based on functionalized gold substrate and the second one on immobilized gold nanoparticles. For the first biosensor, the gold substrate was functionalized with acid–thiol using the self-assembled monolayer technique, while the second one was functionalized with gold nanoparticles immobilized on modified gold substrate. A polyclonal anti-
Escherichia coli antibody was immobilized for specific (
E. coli) and non-specific (
Lactobacillus) bacteria detection. Detection limit with a good reproducibility of 10
4 and 10
3
cfu
mL
−1 of
E. coli bacteria has been obtained for the first biosensor and for the second one respectively. A refractive index variation below 5
×
10
−3 due to bacteria adsorption is able to be detected. The refractive index of the multilayer structure and of the
E. coli bacteria layer was estimated with a modeling software.