This paper introduces a novel fringe field capacitive sensor. To enhance the sensor signal, various sensor electrode design strategies and a surface modification method are introduced, discussed and compared. The sensors are characterized by both simulations and experiments. The experiment results demonstrate the sensor capability of water level measuring. In addition, fringing field sensor of the field strength across the target by the dielectric strength can be used to measure the dielectric constant or component of a solution. The experiment results show that nitrogen plasma surface modification can improve the sensitivity from 69pF/mm to 97pF/mm.