A novel functionalized pillar[5]arene for forming a fluorescent switch and a molecular keypad†
Abstract
We have synthesized a novel functionalized pillar[5]arene (PC5) and used it for fluorescent detection of iron ions (Fe3+). It displays a specificity response for iron ions over other common cations (Hg2+, Co2+, Ca2+, Ni2+, Pb2+, Cd2+, Zn2+, Cr3+, Cu2+, Mg2+ and Ag+) in a solution of DMSO/THF (1 : 4, v/v). Competitive cations did not show any significant changes in emission intensity and the fluorescence spectra detection limit was 1.25 × 10−8 M, indicating the high selectivity and sensitivity of the sensor to Fe3+. It is well known that H2PO4− has a binding ability with Fe3+ to form the complex (Fe(H2PO4)3), so we designed a fluorescent switch and a molecular keypad of PC5 between Fe3+ and H2PO4−. Furthermore, a thin film based on the PC5 was prepared, which was confirmed to be a convenient test kit for detecting iron ions.