A facile and novel fluorescent sensor for dithionite has been constructed by simultaneously immobilizing dansyl group (fluorescence molecule) and dabsyl group (quencher and recognizing group) on the silicon nanowires (SiNWs) and SiNW arrays surface. This sensor for dithionite exhibited high selectivity and a good relationship of linearity between fluorescence intensities and dithionite concentrations from 0.1 to 1 mM. This approach is straightforward and does not require complicated synthesis, which can be extended to develop other sensors with similar rationale. (C) 2018 Elsevier B.V. All rights reserved.