Author Affiliations
1Department of Engineering, University of Campania Luigi Vanvitelli, Aversa 81031, Italy2Department of Physics E. Pancini, University of Naples Federico II, Naples 80126, Italy3Moresense Srl, Filarete Foundation, Milan 20139, Italyshow less
Fig. 1. Schematic cross section of the studied plasmonic GNG-based sensors.
Fig. 2. Plasmonic spectra obtained with water (n=1.332) as surrounding medium for three different period P values: 500 nm, 1 μm, and 1.5 μm.
Fig. 3. Numerical results for three configurations with different P values (500 nm, 1 μm, and 1.5 μm) at a fixed W=400 nm and T=40 nm. (a) Absolute value of the variations in resonance wavelength (|Δλ|) calculated with respect to the water (n=1.332) versus the refractive index along with the linear fitting of the simulated data. (b) Full width at half maximum (FWHM) versus refractive index.
Fig. 4. Numerical results for three configurations with different W values (W=200 nm, W=400 nm, and W=600 nm) at a fixed P=1 μm and T=40 nm. Absolute value of the variations in resonance wavelength (|Δλ|) calculated with respect to the water (n=1.332) versus the refractive index along with the linear fitting of the simulated data.
Fig. 5. Numerical results for three configurations with different W values (W=200 nm, W=400 nm, and W=600 nm) at a fixed S = 600 nm and T=40 nm. Absolute value of the variations in resonance wavelength (|Δλ|) calculated with respect to the water (n=1.332) versus the refractive index along with the linear fitting of the simulated data.
Fig. 6. Simulated absolute value of the resonance wavelength variation in the refractive index range between 1.332 and 1.363, for different values of gold thickness (ranging from 30 to 60 nm), deposited on the optimized nanograting structure.
Fig. 7. Outline of the plasmonic sensor fabrication.
Fig. 8. (a) Outline of the specially designed transmission-based experimental setup. (b) Zoom on the specially designed 3D-printed metallic (AISI 316 steel) holder with the PMMA chips and POFs.
Fig. 9. SEM image of the fabricated gold nanograting.
Fig. 10. (a) Plasmonic spectra obtained at different refractive indices. (b) Absolute value of the resonance wavelength shift (|Δλ|) with respect to water (n=1.332) and linear fitting of the experimental values with error bars.
Fig. 11. (a) SEM image and (b) normalized plasmonic spectra at varying external refractive index relative to non-periodic configuration 1.
Fig. 12. (a) SEM image and (b) normalized plasmonic spectra at varying external refractive index relative to non-periodic configuration 2.
Fig. 13. (a) SEM image and (b) normalized plasmonic spectra at varying of the external refractive index relative to periodic configuration 1.
Fig. 14. (a) SEM image and (b) normalized plasmonic spectra at varying external refractive index relative to periodic configuration 2.
Fig. 15. Absolute value of the variation in resonance wavelength (|Δλ|) calculated with respect to water (n=1.332) for the optimized and non-optimized configurations.
Fig. 16. (a) Outline of the functionalized surface and (b) plasmonic spectra obtained at different BSA protein concentrations. Inset: zoom-in of the resonance region.
Fig. 17. Absolute value of resonance wavelength variation (|Δλ|), with respect to the blank, versus the concentration of BSA protein, with the Langmuir fitting of the experimental values and error bars, in semi-log scale.
Plasmonic Sensor Technology | Bulk Sensitivity [nm/RIU] | Reference |
---|
Gold nanocone arrays on glass substrate | 417 | D. Kawasaki et al. [41] | Gold nanohole arrays | 481 | H. Im et al. [45] | Periodic gold nanorings on quartz substrate | 544 | S. Wang et al. [60] | Nanocavities array on glass substrate | 360 | Cattoni et al. [61] | Gold nanograting on PMMA slab waveguide | 547 | This work |
|
Table 1. Bulk Sensitivity of Several Plasmonic Sensors
[nm] | [nM] | Statistics |
---|
Red. Chi-Sqr | Adj R-Square |
---|
| | 0.009 | 0.99 |
|
Table 2. Parameters of the Langmuir Fitting (GNG-MIP-Based Platform)
Configuration | LOD | BSA Detection Range | Reference |
---|
SPR-POF-MIP | 0.37 μM | 0.37–6.5 μM | [57] | Fluorescence sensor | 10 nM | 0.01–2 μM | [62] | Aggregation-induced emission biosensor coupled with graphene-oxide | 0.4 μM | 0.4–1.5 μM | [63] | optical fiber | 4.36 nM | 4.36–750 nM | [64] | LSPR based on bimetallic nanoparticles | 0.15 pM | 150–15,000 pM | [65] | GNG-MIP-based | 37 pM | 0.037–100 nM | This work |
|
Table 3. Comparative Analysis among Several Sensor Configurations for Selective BSA Detection