Solid Phase Synthesis of N-Alkyl-bis-O-aminobenzamides for Metal Ion Sensing Based on a Fluorescent Dansyl Platform

摘要

In this paper,we report the synthesis on Merrifield's resin of alkyl-bis-o-aminobenzamides labeled with a fluorescent dansyl group for use in metal ion recognition.The influence of alkyl groups with different long chains(n-1,2,4,6)on the spectral fluorescence characteristics was studied.The sensing properties of the beads were evaluated by packing the resins into a flow-through cell for use in a FIA(flow injection analysis)format.Results demonstrated that for those materials with a longer alkyl chain,the fluorescence emission increased upon Li~+,Na~+,K~+,Ca~(2+),and Mg~(2+)addition with a higher sensitivity for Mg~(2+).On the contrary,a fluorescence quenching was observed when Cu~(2+),Fe~(3+),or Zn~(2+)ions were added.The potential applicability of the sensing approach described in this paper for magnesium ions and the sensing response mechanism are outlined.