Plasmonic nanobiosensor based on Au nanorods with improved sensitivity: A comparative study for two different configurations.
Anal Chim Acta
; 1084: 71-77, 2019 Nov 25.
Article
em En
| MEDLINE
| ID: mdl-31519236
Biosensors presenting high sensitivity for the detection of biomolecules are very promising for diseases diagnosis. Nowadays, there is a need for the development of biosensors with fast, trustworthy diagnosis and mostly with low cost, mainly for applications in developing countries. Label-free plasmonic biosensors are good candidates to reach out all these characteristics due to the possibility of spectral tunability, fast sensor response, real-time detection, strong enhancement of the local electric field and excellent adaptability to assemble different nanobiotechnology architectures. In this paper, two different configurations for LSPR based biosensor were developed by using solution-phase gold nanorods (S-P-AuNRs) and AuNRs-chip. The LSPR sensitivities were evaluated by monitoring shifts in the longitudinal plasmon band with changes in the refractive index of the medium surrounding the nanoparticles. AuNRs-chip presented higher sensitivity of 297â¯nm RIU-1 (refractive index unit) against 196â¯nm RIU-1 for S-P-AuNRs. Figure of merit (FOM) for AuNRs-chip and S-P-AuNRs were 3.0 and 2.2 RIU-1, respectively. This result was assigned to the coupling of the lower energy longitudinal LSPR mode of propagation for AuNRs-chip among nearby nanoparticles in the film. In addition, an improvement of at least 18% in sensitivity was obtained comparing to others AuNRs based assay with similar aspect ratio. FOM is more appropriate to compare different approaches, in this case, the proposed biosensor reached improvements of at least 114%, presenting higher values even when compared to AuNRs of higher aspect ratio. As a proof of concept, AuNRs surface was chemically modified using mercaptoundecanoic acid followed activation with ethylcarbodiimide and N-hidroxysuccinimide to allow the interaction between Bovine Serum Albumin (BSA) antibody and correspondent antigen. Both configurations studied resulted in efficient plasmonic biosensors, presenting high sensitivity for changes in the refractive index and for surface binding with anti-BSA.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Técnicas Biossensoriais
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Nanotecnologia
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Nanotubos
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Ouro
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Anticorpos
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Antígenos
Tipo de estudo:
Diagnostic_studies
Limite:
Animals
Idioma:
En
Revista:
Anal Chim Acta
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Holanda