Naked-Eye Detection of Water Contaminants Enabled by Engineered Plasmonic Resonance in Hybrid Detector Systems

The quality of water supply and its contamination remain global issues. In this work we aim to propose a concept of a novel integrated device for label-free and real-time monitoring of water contaminants that may be performed without specialized equipment. By employing an effective model for describing interactions of a plasmonic nanoparticle-based sensing reflector and using a transfer matrix approach to determine optical properties of the complete system, we demonstrate that our integrated sensing device is able to change the color of emitted light in response to the change of optical properties of the surrounding medium, which enables naked-eye detection of water contaminants. Additionally, by employing dual plasmon resonance arising from resonances of nanoparticles and metal substrate, as well as interactions between them, it is possible to engineer emission efficiency and colorimetric properties of the sensor. We believe that the proposed device, due to its compactness, integrated form, and naked-eye and real-time detection capabilities, will address the current challenges in water quality monitoring.