Increasing demands in thefield of sensing, especially for gas detectionapplications, require new approaches to chemical sensors. Metal−organic frameworks (MOFs) can play a decisive role owing to their outstanding performances regardinggas selectivity and sensitivity. The tetrathiafulvalene (TTF)-infiltrated MOF, Co-MOF-74, has been prepared following the host−guest concept and evaluated inresistive gas sensing. The Co-MOF-74-TTF crystal morphology has beencharacterized via X-ray diffraction and scanning electron microscopy, while thesuccessful incorporation of TTF into the MOF has been validated via X-rayphotoemission spectroscopy, thermogravimetric analysis, UV/vis, infrared (IR), andRaman investigations. We demonstrate a reduced yet ample uptake of CO2in thepores of the new material by IR imaging and adsorption isotherms. Thenanocomposite Co-MOF-74-TTF exhibits an increased electrical conductivity incomparison to Co-MOF-74 which can be influenced by gas adsorption from asurrounding atmosphere. This effect could be used for gas sensing.