It is well established that the dispersion of nanosized metal particles in a polymer matrix can induce nonlinear optical properties, yet very little is known about the effect of semiconducting transition metal oxide nanoparticles on luminescence properties of conjugated polymers. In this paper, we report the synthesis of a nanostructured /poly(p-phenylenevinylene) (PPV) system and show by diffuse reflectance infrared Fourier transform spectrometry that a stable conjugated nanocomposite is obtained. Investigation of the photoluminescence (PL) properties reveals both a broadening and a blueshift of the emission spectra. Adsorption of oxygen is found to be stronger on the nanocomposite than on PPV and to reversibly quench the PL emission, thus suggesting enhanced gas sensing properties. A tentative mechanism explaining the role of n- is briefly discussed.