A sensor device is provided for determining the presence and/or amount of at least one component in a fluid. The sensor device comprises at least one sensor unit, the at least one sensor unit comprising at least one elongated nanostructure and a dielectric material surrounding the at least one elongated nanostructure. The dielectric material is such that it is selectively permeable for one of the at least one component and is capable of sensing the component permeated through the dielectric material. The sensor device according to preferred embodiments shows good sensitivity and good mechanical strength. The present invention furthermore provides a method for manufacturing such a sensor device and a method for determining the presence and/or amount of at least one component in a fluid using such a sensor device.