LAUSR

In this study, we have designed and synthesized a novel 'AND' logic based fluorescence probe,1-(3',6'-bis((tert-butyldiphenylsilyl)oxy)-3-oxospiro (isoindoline-1,9'-xanthen)-2-yl)-3-phenylthiourea (FPSi), for the rapid (3 min) simultaneous detection of F- and Hg2+ in DMSO/H2O solution (7:3, v/v). The FPSi probe, synthesized over three steps starting from commercially available fluorescein, was constructed by attaching tert-butyldiphenylsilyl and thiosemicarbazide (as the specific identification groups for F- and Hg2+) to the skeleton of fluorescein, respectively. FPSi produced no fluorescence response towards the addition of F- or Hg2+ separately. However, when the probe was exposed to a solution containing both F- and Hg2+, there was a significant yellow-green fluorescence. FPSi demonstrated an excellent selectivity towards both F- and Hg2+ in the presence of interfering substances. The results of TOF-MS-EI analysis indicated that the response of FPSi towards F- and Hg2+ was mainly aroused by the F- promoted cleavage of Si-O bond, and Hg2+ triggered an irreversible desulfurization reaction leading to the spiral ring opening. Furthermore, the FPSi probe has been successfully used to detect F- and Hg2+ ions in tap water and cropland soil.