In this Letter, we demonstrate strong light emission from defective hexagonal boron nitride (hBN) defect centers upon their coupling with disorder near-touching plasmonic units. Based on numerical simulations and characterization results, the plasmonic design at thin layer thicknesses of 20 nm can provide above 2 orders of magnitude enhancement in photoluminescence (PL) spectra. Moreover, this plasmonic platform shortens the luminescence lifetime of the emitters. The proposed design can be easily extended to other plasmonic-emitter combinations where strong light–matter interaction can be achieved using large-scale compatible routes.

The colorimetric detection of bio-agent targets has attracted considerable attention in nanosensor designs. This platform provides an easy to use, real-time, and rapid sensing approach, as the color change can be easily distinguished by the naked eye. In this Letter, we propose a large scale compatible fabrication route to realize colorimetric optical nanosensors with a novel configuration. For this purpose, we design and fabricate a tightly packed disordered arrangement of Fabry–Perot based metal–insulator–metal nanoantennas with a resonance frequency at visible light wavelengths. In this design, the adsorbed bio-agent changes the effective refractive index of the cavity, and this causes a shift in the resonance wavelength. The experimental data show that the proposed design can have sensitivity values > 70 n m / r e f r a c t i v e index unit. Unlike other optical sensing schemes that rely mainly on hot spot formation and field enhancement, this design has a large active area with relatively uniform patterns that make it a promising approach for low-level and reliable bio-detection.