Novel Highly Sensitive Protein Sensors Based on Tapered Optical Fibres Modified with Au-Based Nanocoatings

Figure 4

Transmission spectra of (a) and (b) measured before modification: black line, in water, magenta line, in air, red line, after deposition of the SiO₂ thin film, and blue line, after deposition of the Au thin film.

(a)

(b)