A device for detecting the concentration of biological materials is formed in a body having a plurality of fluidic paths connectable to a multi-microbalance structure carrying a plurality of microbalances, each microbalance having a sensitive portion facing a reaction chamber. The body and the multi-microbalance structure are configured to be mechanically coupled together and each microbalance is configured to be coupled to a respective fluidic path. Each fluidic path includes an inlet, a duct and a liquid waste, each duct being configured to be coupled with a respective reaction chamber. The plurality of fluidic paths and microbalances form at least one first and one second reference cells and one first sample cell.