A nanochannel apparatus and method of fabrication provide an array of nanochannels with distal open or exposed ends formed in situ through a permanent support. A nanofluidic system includes the nanochannel apparatus, a fluidic interface, and a component interfaced to the nanochannel apparatus. The method includes encasing an array of nanowires in a support, and forming the array of nanochannels in situ in locations of the nanowires, such that distal ends of the nanochannels are exposed.