Fig. 1. NHMM sensor integrated with microfluidics. (a) Schematic diagram of the NHMM sensor with a liquid flow channel and an SEM image of the fabricated nanorod array with a consistent period of 210 nm, diameter of 150 nm, and average height of 350 nm (scale bar, 1 µm). (b) Photo of the NHMM sensor and a prism integrated with a microfluidics system.

Fig. 2. Schematic diagram of the process of fabricating the NHMM.

Fig. 3. SEM images of the fabricated gold nanorod array by combining EBL and electroplating. (a) The electric quantity is appropriate, and the nanorods reach the expected height. (b) Over electroplating: the electric quantity is too large and the nanorods overflow. (c) Large-area sample grown under a suitable electric quantity. All pictures were taken at a depression angle of 45°.

Fig. 4. (a) Resonance wavelength and wavelength shift (Δλ) with various heights of the nanorod. The period and radius of the nanorods are 210 nm and 75 nm, respectively. (b) Resonance wavelength and Δλ with various filling factors of the nanorod. The height of the nanorod is 350 nm. The wavelength shift is the difference between the resonance wavelengths when the refractive index of the analyte is 1.3329 and 1.3323.

Fig. 5. (a) Simulated and (b) experimental reflectance of the plasmonic NHMM sensor in deionized (DI) water and 0.5% glycerin in DI water. The simulation parameters are as follows: the period, height, and radius of the nanorods are 210 nm, 350 nm, and 75 nm, respectively. (c) The curve of the simulated electric field intensity with z at different incident angles. z represents the distance from the top of the nanorod. (d) The wavelength shift measured with DI water and 0.5% glycerin solution at different incident angles.

Fig. 6. Simulation diagram of the electric field at the resonance wavelength.

Fig. 7. (a) Simulated reflectance of the plasmonic NHMM sensor in DI water and 0.5% glycerin in DI water. The model with the addition of the five gold nanocones to the top of the nanorod to simulate the tips produced in the manufacturing process is shown in the inset. The base and top radii of the nanocones are 15 nm and 1 nm, respectively, and the height of the nanocones is 20 nm. (b) A cross-sectional electric field diagram at the top of the nanocones.

Fig. 8. (a) Schematic diagram of bio-functionalization on the NHMM biosensor. (b) and (c) Sensorgrams for real-time detection of different concentrations of streptavidin. (d) Wavelength shift as a function of streptavidin concentration, and the error bars represent the standard deviation. The red curve was fitted by the Hill equation. (e) Sensorgrams for detecting 20 µg/mL streptavidin by 50 nm gold film PSPR biosensor.

Fig. 9. Variation of the wavelength shift in the presence of the PBS, the 50 µg/mL BSA, and the streptavidin over time.

Fig. 10. Schematic diagram showing the setup used for reflectivity measurements.

Fig. 11. Schematic diagram of the cross-section of the microfluidic system.