The invention concerns a sensor device (1) for detecting the presence of one or more molecules (20) and/or of a class of molecules (20); comprising at least one first (nano-) structure (2); at least one second structure (3); at least one joining portion (4) respectively connecting the at least one first (nano-)structure (2) and the at least one second structure (3) and configured to allow a relative mobility between the at least one first (nano-)structure (2) and the at least one second structure (3), wherein the at least one joining portion (4) is an element separate from and connected to the at least one first (nano-)structure (2) and the at least one second structure (3) or wherein the at least one joining portion (4) is formed integrally with the at least one first (nano-)structure (2) and/or with the at least one second structure (3); one binding structure (5), especially one binding structure (5) per joining portion (4), configured to bind with a molecule, the presence of which is to be detected, wherein the binding structure (5) is located on the at least one first (nano-)structure (2) or on the at least one second structure (3) or on the at least one joining portion (4) such that said allowed relative mobility between the at least one first (nano-)structure (2) and the at least one second structure (3) is changed, especially limited, in a bound state of the binding structure (5) as compared to an unbound state of the binding structure (5); and a detecting means (100) for detecting said relative mobility between the at least one first (nano-)structure (2) and the at least one second structure (3).