Tin doped Manganese dioxide/CNT nanocomposites (Sn-MnO2/CNT) were synthesized and utilized as an adsorbent as well as electro-catalyst for direct redox sensing of Thiourea. Simple co-precipitation route at low temperature was followed to prepare the nanocomposite. The synthesized composites characterized for their morphology, compositional structure and optical properties and were used as an efficient adsorbent for the removal of Indigo carmine dye. The impact of parameters comprising initial pH, amount of adsorbent and initial dye concentration wit contact time were examined to procure the optimum adsorption conditions. The isotherm evaluations concluded that the Langmuir model fits better to the experimental data. Further, the prepared Sn-MnO2/CNT nanocomposites were employed as a smart chemical sensor to detect Thiourea in aqueous medium. The fabricated sensor exhibited a good sensitivity and detection limit of 6.22 mu A/mu cm(2) and 0.68 mu M, respectively.