Summary: In this work we propose a sensor made of a spin trap (iron(II)-diethyldithiocarbamate complex, FeDETC) encapsulated in a latex rubber matrix. Latex was used as solid matrix due to its excellent mechanical properties, biocompatibility and natural angiogenic properties. The fabrication and optimization processes were done by varying: FeCl 3 6H 2 O and DETC concentrations in the system, polymerization temperature, FeDETC/latex ratio. The sensor presents high stability, the observed Electron Paramagnetic Resonance signal can be detected even after the sensor is exposed to ambient atmosphere for 40 days. It can be reused and is able to measure NO concentration as low as 0,1 mM. These results make NO-FeDETC in the rubber matrix a promising NO sensor.