An apparatus, according to one aspect, may include a chromatograph and a bulk acoustic resonator. The chromatograph may include a channel that is defined at least partially in a monolithic substrate. The channel may have an inlet to receive a sample and an outlet. A chromatography material may be included in the channel. The bulk acoustic resonator may have a first electrode and a second electrode that has a chemically functionalized surface. The chemically functionalized surface may be included in a chamber that is defined at least partially in the monolithic substrate and that is coupled with the outlet of the channel. Methods of making and using such apparatus, and systems including such apparatus, are also disclosed.