A capacitive sensor based on porous silicon (PSi) for detection of various polar (ethanol, methanol, acetone, acetonitrile, chloroform) and non-polar organic solvents (n-hexane, toluene) was described. The meso-PSi layer with an average pore size of 30 nm was prepared by a galvano static electrochemical etching of crystalline silicon in HF-based solution. Surface passivation was conducted by anodic oxidation process and the electrical contacts were made exclusively onto the front porous structure. The asfabricated sensor exhibits highly sensitive and reversible response toward polar organic molecules during the real-time measurements of capacitance, whereas the capacitive sensing behavior was irreversible and opposite in direction in case of non-polar solvents. The response time was in the order of acetone < methanol < acetonitrile < ethanol < chloroform. The observed response could be understood as the impact of charge redistribution on the pore walls upon organic infiltration, along with changes in the dielectric constant of the porous layer. A comparative study of such different responses is provided. Excellent repeatability of the device was obtained after twelve cyclic tests of acetone, demonstrating stability of the sensor. Long-term stability for the sensor was also observed after four weeks storage. The present approach is useful for the development of a simple, cost-effective sensor for detection of various chemical analytes. (C) 2014 Elsevier B.V. All rights reserved.