Controlled dye release from a metal-organic framework: a new luminescent sensor for water

Fan Xiao; Jun Zhang; Jiulin Gan; Ying Tang; Yuanjing Cui; Yang Yu; Guodong Qian

doi:10.1039/c9ra08753b

Controlled dye release from a metal-organic framework: a new luminescent sensor for water

RSC Adv. 2020 Jan 15;10(5):2722-2726. doi: 10.1039/c9ra08753b. eCollection 2020 Jan 14.

Authors

Fan Xiao¹, Jun Zhang¹, Jiulin Gan², Ying Tang¹, Yuanjing Cui¹, Yang Yu¹, Guodong Qian¹

Affiliations

¹ State Key Laboratory of Silicon Materials, Cyrus Tang Center for Sensor Materials and Applications, School of Materials Science & Engineering, Zhejiang University Hangzhou 310027 China cuiyj@zju.edu.cn gdqian@zju.edu.cn.
² State Key Laboratory of Luminescent Materials and Devices, Institute of Optical Communication Materials, South China University of Technology Guangzhou 510640 China.

Abstract

By introducing the dye Rhodamine 6G (R6G) into a metal-organic framework (MOF), Mn-sdc-2 (H₂sdc = 4,4'-stilbenedicarboxylic acid), with a pore size of 20 × 9.8 Å², the composite R6G@Mn-sdc-2 was obtained. Subsequently, the MOF Mn-sdc-1 with a smaller pore size of 7.5 × 7.5 Å² can be formed through a single-crystal to single-crystal transformation from Mn-sdc-2, thus tightly locking the dye R6G within the pores. Compared with R6G@Mn-sdc-2, R6G@Mn-sdc-1 exhibits a stronger fluorescence emission of R6G. Because the MOF Mn-sdc-1 can reversibly transform back to Mn-sdc-2 in the presence of trace water, the dye R6G can be released. This enables R6G@Mn-sdc-1 to be used as a new luminescent sensor for trace water in organic solvents by monitoring the fluorescence intensity of released R6G. The limit of detection can reach 0.035% in ethanol (v : v), which is among the most sensitive fluorescent water probes.