Metal-organic framework coated planar polymer optical waveguide for carbon dioxide detection and sensing

We present a simple gas sensor based on planar polymer optical waveguides with MOF (ZIF-8) coating for carbon dioxide detection and sensing. The optical waveguides were made of PMMA and fabricated by hot embossing replication. A thin MOF film was uniformly grown on the waveguide sample surface through a simple solution method, which is crucial for the envisioned production of MOF-based sensing devices on large scale. The experimental results show that the produced optical elements exhibit high sensitivity and selectivity of CO2 gas with rapid response time and excellent reversibility of adsorption and desorption of the gas molecules. The demonstrated planar polymeric sensing devices provide the potential to develop flexible onchip gas sensors in an inexpensive and reproducible way.