A flow cell for a liquid chromatography detector comprises a substrate formed of a glass material; a fluidic channel extending through the substrate; and at least one gas filled region formed in the substrate along at least a portion of a length of the fluidic channel. A portion of the glass material separates the fluidic channel and the gas filled region. An interface between the gas filled region and the portion of the glass material separating the fluidic channel and the gas filled region enables total internal reflection of light propagating along the fluidic channel.