8 mm long channel waveguides were manufactured in polycrystalline diamond with inductively coupled plasma etching and characterized in terms of mode-profile and propagation loss in the 1.5 - 3.4 mu m spectral region. As proof of principle, the waveguides were evaluated in an evanescent field sensing setup targeting the CH absorption peak of isopropanol at similar to 3.4 mu m, showing good agreement with numerical finite element simulations. (C) 2016 Optical Society of America