A nano-sensor including a substrate including pores formed thereon and a detecting mechanism for detecting changes in capacitance due to the presence of a substance. A method of measuring humidity by sampling air with the nano-sensor, detecting changes in capacitance, and determining the relative humidity of air. A method of detecting the presence of a substance by taking a sample with the nano-sensor, detecting changes in capacitance, and determining the presence of a substance. A method of making the nano-sensor by forming nano-pores on a substrate, and forming, on the surface of the substrate, a detecting mechanism for detecting changes in capacitance due to the presence of a substance.