Microfluidic patch for separating specific species in biological fluids, said patch comprising: - a flow layer extending along a longitudinal direction in a planar fashion, said flow layer being configured to allow a biological fluid to flow through along said longitudinal direction, said flow layer being also configured to provide from a starting biological fluid an outgoing flow to be detected; said flow layer comprising: - a first porous portion having at least one part configured to receive and carry along the longitudinal direction the starting biological fluid containing related species; - a multilayer membrane in fluid communication with the first porous portion and placed downstream the first porous portion along the longitudinal direction, the multilayer membrane comprising a plurality of graphene-based sheets parallel to each other, the graphene-based sheets being spaced among each other so as to define a plurality of parallel channels extending along the longitudinal direction and transversally interconnected among each other, the graphene-based sheets being chemically functionalized so as to act as sieve to provide from the starting biological fluid an outgoing flow of specific species to be detected; - a second porous portion in fluid communication with the multilayer membrane, said second porous portion being placed downstream the multilayer membrane along the longitudinal direction, the second porous portion being configured to receive and carry along the longitudinal direction the outgoing flow to be detected; - two first electrodes (6A, 6B) comprising a first upstream electrode and a first downstream electrode placed respectively upstream and downstream the multilayer membrane, said first electrodes (6A, 6B) being configured to apply an electric bias to foster the flow through said multilayer membrane from the first porous portion to the second porous portion; - two hydrophobic layers sandwiching the flow layer and extending along the longitudinal direction in a planar fashion, said two hydrophobic layers fully enclosing the multilayer membrane and enclosing at least partially the first and the second porous portions (3, 5). - a flow layer extending along a longitudinal direction in a planar fashion, said flow layer being configured to allow a biological fluid to flow through along said longitudinal direction, said flow layer being also configured to provide from a starting biological fluid an outgoing flow to be detected; said flow layer comprising: - a first porous portion having at least one part configured to receive and carry along the longitudinal direction the starting biological fluid containing related species; - a multilayer membrane in fluid communication with the first porous portion and placed downstream the first porous portion along the longitudinal direction, the multilayer membrane comprising a plurality of graphene-based sheets parallel to each other, the graphene-based sheets being spaced among each other so as to define a plurality of parallel channels extending along the longitudinal direction and transversally interconnected among each other, the graphene-based sheets being chemically functionalized so as to act as sieve to provide from the starting biological fluid an outgoing flow of specific species to be detected; - a second porous portion in fluid communication with the multilayer membrane, said second porous portion being placed downstream the multilayer membrane along the longitudinal direction, the second porous portion being configured to receive and carry along the longitudinal direction the outgoing flow to be detected; - a first porous portion having at least one part configured to receive and carry along the longitudinal direction the starting biological fluid containing related species; - a multilayer membrane in fluid communication with the first porous portion and placed downstream the first porous portion along the longitudinal direction, the multilayer membrane comprising a plurality of graphene-based sheets parallel to each other, the graphene-based sheets being spaced among each other so as to define a plurality of parallel channels extending along the longitudinal direction and transversally interconnected among each other, the graphene-based sheets being chemically functionalized so as to act as sieve to provide from the starting biological fluid an outgoing flow of specific species to be detected; - a second porous portion in fluid communication with the multilayer membrane, said second porous portion being placed downstream the multilayer membrane along the longitudinal direction, the second porous portion being configured to receive and carry along the longitudinal direction the outgoing flow to be detected; - two first electrodes (6A, 6B) comprising a first upstream electrode and a first downstream electrode placed respectively upstream and downstream the multilayer membrane, said first electrodes (6A, 6B) being configured to apply an electric bias to foster the flow through said multilayer membrane from the first porous portion to the second porous portion; - two hydrophobic layers sandwiching the flow layer and extending along the longitudinal direction in a planar fashion, said two hydrophobic layers fully enclosing the multilayer membrane and enclosing at least partially the first and the second porous portions (3, 5).