Abstract: The invention provides a device for determining the type of protein in a liquid, the device comprising (a) an immobilized ATP dependent protease based molecular transporter machine configured to guide a protein that is functionalized with labels through a detection area of a detector, (b) said detector, configured to detect a signal as function of the labels of the labelled amino acids, (c) a processor unit, configured to identify from the detector signal a sequence of amino acids of the functionalized protein, wherein the processor unit is further configured to compare the identified sequence of amino acids with the occurrence of such sequence in a database of proteins and to identify the type of protein.