Plasmonic nanobiosensor based on Au nanorods with improved sensitivity: A comparative study for two different configurations
| Autor: | Gustavo F. S. Andrade, Linus Pauling F. Peixoto, Jacqueline Ferreira Leite Santos |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Surface Properties
Nanoparticle 02 engineering and technology Biosensing Techniques 01 natural sciences Biochemistry Antibodies Analytical Chemistry Environmental Chemistry Nanobiotechnology Animals Nanotechnology Sensitivity (control systems) Antigens Spectroscopy Plasmon Nanotubes business.industry Chemistry 010401 analytical chemistry Serum Albumin Bovine 021001 nanoscience & nanotechnology Aspect ratio (image) 0104 chemical sciences Optoelectronics Nanorod Cattle Gold 0210 nano-technology business Refractive index Biosensor |
| Zdroj: | Analytica chimica acta. 1084 |
| ISSN: | 1873-4324 |
| Popis: | 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 297 nm RIU−1 (refractive index unit) against 196 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. |
| Databáze: | OpenAIRE |
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