A nanofluidic structure including a semiconductor substrate and a dielectric layer positioned above and in contact with the semiconductor substrate. A first reservoir and a second reservoir are defined by the semiconductor substrate and the dielectric layer. The second reservoir is spaced apart from the first reservoir. Bottom passage fins protrude from the semiconductor substrate and extend from the first reservoir to the second reservoir. Top passage fins, above and spaced apart from the bottom passage fins, extend from the first reservoir to the second reservoir. Nanofluidic passages between the top and bottom fins connect the first reservoir and the second reservoir. Each of the nanofluidic passages includes a bottom wall, a top wall and sidewalls. The bottom wall is defined by a respective bottom passage fin. The top wall is defined by a respective top passage fin. The sidewalls are defined by the dielectric layer.