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Detecting volatile organic compounds (VOCs) is important, their presence in modern indoor environments being associated to health risks including respiratory diseases and cancers. State-of-the-art VOCs sensors as MEMS and semiconductor devices achieve high sensitivity but exhibit poor selectivity and high cross-sensitivity with other environmental analytes including temperature and humidity. Such sensors often require complex and costly fabrication/operation processes and/or expensive readout equipment. Here, a novel optomechanical sensing platform, based on the combination of a holographic diffractive element and a static deflection bilayer cantilever, is presented. Its operation principle is based on the differential response of the cantilever layers to target analytes, and was verified using COMSOL Multiphysics. The cantilever deflection due to analyte presence was visually measured. As the sensitive layer is a photopolymer, a transmission volume holographic diffraction grating was recorded enabling a second, more sensitive, detection mode based on the variations in the diffracted beam intensity as the cantilever deflection angle changes. We compared the sensitivity of the optomechanical holographic sensor configuration to that of a holographic diffraction grating in a photopolymer layer coated on a glass slide. Selectivity and sensitivity of both configurations was increased by doping the photopolymer matrix with zeolite nanoparticles. The initial tests monitored the diffraction efficiency changes during the 5 minutes exposure time to 1000 ppm ethanol. The TOS presented changes of 1–4% in diffraction efficiency depending on the dopant concentration and photopolymer layer thickness, while the optomechanical sensor exhibited 7–14% change in diffraction efficiency.
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