High-Throughput Label-Free Detection Using a Gold Nanoslit Array With 2-D Spectral Images and Spectral Integration Methods

We fabricated gold nanoslit arrays and experimentally compared the sensing capabilities using the single-polarization and multipolarization spectral integration methods. The signal-to-noise ratio and refractive index detection limit using the multipolarization method were increased to three times larger than the simple integration method. Combining 2-D spectral images and the spectral integration method, we demonstrated real time and multiple detections of 30-nm-gold nanoparticles. The detection limit of the system is down to 0.147 particles/μm².