A method and device for sequencing at least a fragment of a linear polymer. The device comprises a well for placement of a rotaxane comprising the combination of a cyclic molecule and a linear polymer threaded through said cyclic molecule; a probe having the ability to move the linear polymer relative to the cyclic molecule while producing a signal resulting from the interaction of the cyclic molecule and a unit attached to the polymer; and means for reading said signal. The process comprises formation of the rotaxane, attachment of the probe, movement of the cyclic molecule relative to the linear polymer and the reading of signals. The device and method are especially useful for the sequencing of DNA.