The development of an efficient sensor for the determination of the DMSO content in aqueous solution is highly desirable in a number of chemical industries. Presented herein is a ferrocene-conjugated iridium(III) complex, which exhibits remarkable capability to detect traces of DMSO (< 1% v/v) in aqueous solution through a turn-on luminescence sensing mechanism. The extraordinary sensitivity and selectivity of this newly developed complex for DMSO renders it as one of the most powerful DMSO sensors known. (C) 2017 Elsevier B.V. All rights reserved.